Exhaust question

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VWcorvette
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Exhaust question

Post by VWcorvette »

Putting the engine from my 75 Vette (GM crate 350) into a 92 Safari. Can I use the headers that I had on the Vette? What are the clearance issues? I would like to run them to side pipes actually.
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Re: Exhaust question

Post by Mmusicman »

I can't say if you're Vette headers will fit or not, but you can temporarily mount them to engine first, then temporarily see if the block will drop in place with them attached. This is how I plan to "test fit" a set of Super-Comp Hookers. Once decided, the motor can definitely be installed with the headers fully attached and already torqued down. This (along with plugs already installed) really makes for a much easier installation with so much less work. Tip: remove the 2 nuts for the brake master cylinder and push it to the side (with lines still attached) for a little more wiggle room. Lift the van at highest angle possible for easy installation. I don't pull the bumper either.

The popular solution is to run the Hedman #68600 block huggers. I currently have them on my 92 Astro 350. They fit GREAT!!!

I'm currently running true-dual exhaust out each side (exit before rear tires) and have also considered side pipes. Old school rules!
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2000 Chevy Astro LS AWD | 31" LT265/70R17 Tires | 8" LIFT | 10" TOTAL
92 Chevy Astro Shorty | V8-350
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Re: Exhaust question

Post by VWcorvette »

Haha, I just read your entire build thread. Very inspiring. I am following your lead. I am considering the Hedmans but am trying to keep costs down. The engine and headers came from my Vette. My budget is $2016. I'm entering the Grassrootsmotorsports.com challenge so I have to watch where I spend money. A used set of headers might work.

I intend to do side pipes as well!!!!!

Here is the build thread:
https://grassrootsmotorsports.com/forum ... 329/page1/

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Re: Exhaust question

Post by VWcorvette »

BTW, how'd you lower your van?
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Re: Exhaust question

Post by Mmusicman »

VWcorvette wrote:Haha, I just read your entire build thread. Very inspiring. I am following your lead.
My build thread? (on other van forum?)

I read your build thread. What's your current status?
BTW, how'd you lower your van?
Cut off 1 coil in the front. Rear is stock.
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2000 Chevy Astro LS AWD | 31" LT265/70R17 Tires | 8" LIFT | 10" TOTAL
92 Chevy Astro Shorty | V8-350
http://www.CruisinSouthFlorida.com

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Re: Exhaust question

Post by VWcorvette »

Yes, I saw your van and thread on another forum. I was considering cutting a coil as well. I have Corvette sawblades 17x8.5 front and rear. Gonna need spacer/adapters.

You did not flip the rear axle? Interesting.

Currently waiting for it to warm up around here so I can start stripping the front of the van.
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Re: Exhaust question

Post by Mmusicman »

There were NO issues cutting a coil. It's was quite easy and I did it with a cheap air cutting tool. It dropped me about 1 3/4". The ride is essentially unaffected... but possibly a tad bit firmer which is necessary anyway. I love the ride. Won't cost you anything to try!

Yes, the rear is totally stock! I do haul some sound equipment, which brings it down slightly. Otherwise, the 24 year old spring may just be a little sagged naturally... so I'm fine with the stance.

If you have any questions that I didn't address on my build thread... don't hesitate to ask! Like I said, you don't have to pull the bumper... the stock engine can be removed with exhaust manifolds still attached, as well as the V8 dropped back in with headers already attached too. The installation trick is to angle the van up high, and keep chain across manifold to cherry picker as tight as possible if not using a plate. (I think I have photos on my build thread.. which by the way I never finished)

This is the best time of year (for us in South Florida) to do this type job... with temps comfortable in the 80's and sometimes dipping into the 70's. I may temporarily be pulling my V8-350 out next month to deal with a possible gasket issue. While out I want to change the torque converter to a higher stall lockup, and test fit a supercharger as well as some Hooker race headers. I'm contemplating just swapping it with a 400 I have currently sitting on a stand, which might be easier and quicker. As a ready to go swap, it would be done in a weekend. But I do love the way the little 350 runs and sounds now, while still getting great fuel mileage. I'm torn with choices! :)

Here's an older photo of my 400...
Engines-400.jpg
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2000 Chevy Astro LS AWD | 31" LT265/70R17 Tires | 8" LIFT | 10" TOTAL
92 Chevy Astro Shorty | V8-350
http://www.CruisinSouthFlorida.com

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Re: Exhaust question

Post by VWcorvette »

Thanks for the info. Why the torque converter swap? What's the reasoning? Will my 700r4 be okay to back up my mild 350? Rather not spend money where I don't need to right now. Can I use poly motor mounts?
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Re: Exhaust question

Post by Mmusicman »

My V8 has a "medium performance" high-torque/hp cam... which is pretty rough/choppy at idle. Add A/C and I have to keep the idle somewhat higher than I want (in neutral), and sometimes have to take it out of gear at lights to keep it running, while under load. A higher stall (I'm estimating 2400rpm) will address this condition.. as I have used them before. They give you a hell of a launch too... but I already smoke my tires so that won't matter much. I also need to be sure this performance torque converter has lock-up. They start getting a little pricey.

You're 700R4 with stock converter will be excellent behind a mild V8! Assuming it is a later model 700R4, it already has some nice strength improvements over the earlier models. The 700R4 was run from factory behind V8's in earlier full size vans and truck anyways.

You may have an issue with the torque-converter bolt pattern bolting up to an older model flex-plate. My '92 700R4 converter would not bolt up to the stock flexplate of a 70's model V8. Fortunately, I also had an 80's model flex-plate (with dual patterns) that matched up perfectly! Don't get burned on this one... be sure to see if they match up... BEFORE installation.

Poly motor-mounts? I don't see any reason why not! I had also considered it. But be aware because they are so firm, they might cause a little more harshness with vibration... I'm not sure. I've never used them, but I'm sure you could research them. In my case I bought very expensive "factory dealer" mounts (about $60) compared to $5 cheap ones I already had new (and wound up throwing them away). I didn't want mounts that could potentially come apart 6 months down the road... for any price!

Here is a quick little "launch" video of me "parking" in the garage... lol
https://www.youtube.com/watch?v=rXyS6edaAUY
[youtube]rXyS6edaAUY[/youtube]
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2000 Chevy Astro LS AWD | 31" LT265/70R17 Tires | 8" LIFT | 10" TOTAL
92 Chevy Astro Shorty | V8-350
http://www.CruisinSouthFlorida.com
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Re: Exhaust question

Post by WoodButcher »

MM,
you may consider an even higher stall than that, the one I used,
ORE-4L60B-10 Gm 4L60E 1993-1996 (Non-Pwm) Heavy Duty High Stall Torque Converter 2000-2400 282.60 still wants me to hit neutral at the lights with a 650 rpm idle.

VWc,
You'll like the poly mounts. When I did my swap I used poly for every application, motor, body, trans, and suspension. She rides a little stiff but everything is more responsive. Jump the gas and you feel it in your butt, the engine just grabs and it feels great.


I've been looking at sidepipes and all I find is the Patriot w/ glass packs or the straight through lake pipes. Are there others I'm missing?
Is 70" the right length?
'93 Safari shorty, 350 swap
'05 Astro AWD, lifted, 6 liter, cammed, ported and programmed for fast.
'69 G10, straight 6, 3 onatree, jumped at me when I had a pocketful of cash looking for a spare astro. :)
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Re: Exhaust question

Post by Mmusicman »

WoodButcher wrote:I've been looking at sidepipes and all I find is the Patriot w/ glass packs or the straight through lake pipes. Are there others I'm missing?
I pretty much came up with the same results. Lake-Pipes are too small. But I have also considered what I would call a "performance hybrid". The "glass packs" inside the side-pipes are considered somewhat restrictive (with only 1 3/4" ID) which got me thinking... how about running 2 1/2 exhaust through standard or glass-pack mufflers (only a short distance back) and then re-routing their output forward (with U-pipes) and back through the side-pipes... with the restrictive glass packs removed. The side pipes would essentially then become functioning wide open "tail-pipes". The only trick would be to still get the correct glass-pack sound, which could be done through 2 1/2" glass-pack mufflers. The plumbing wouldn't be that complicated at all.

Looks like the Patriots are about the only choice left.
WoodButcher wrote:MM,
you may consider an even higher stall than that, the one I used,
ORE-4L60B-10 Gm 4L60E 1993-1996 (Non-Pwm) Heavy Duty High Stall Torque Converter 2000-2400 282.60 still wants me to hit neutral at the lights with a 650 rpm idle.
According to the specs I see (on their product catalog link)...
if you are using the -10 model... it is a "heavy duty" converter, and not a "high stall" converter (according to their product catalog).
Their "high-stall" uses the suffix "DCNF" ... and not "-10".
Typically... "heavy duty" uses lower stalls for towing, and a high-stall would never be used for this application.

While Oregon Converter may call it a "2000-2400" in one description, they do refer to their "high stall" as a different part number in their catalog. This seems somewhat conflicting and generalized with such a broad stall number. And by your own admission you say your's doesn't seem to stall high enough, which I would expect. Perhaps it stalls at the lower 2000, which is only about 200 more than stock (by my estimations)... or their stall description is in error. I have also discovered that they call the "DCNF" model a "high stall" in their catalog, yet call it a "stock stall" on their product description page. This is definitely very conflicting!

Here is what I'm currently considering: http://www.jegs.com/i/FTI-Transmissions ... 0/10002/-1
or same from Summit: http://www.summitracing.com/parts/fti-s ... /overview/
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2000 Chevy Astro LS AWD | 31" LT265/70R17 Tires | 8" LIFT | 10" TOTAL
92 Chevy Astro Shorty | V8-350
http://www.CruisinSouthFlorida.com
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Re: Exhaust question

Post by WoodButcher »

That would explain the TC, makes all the sense in the world, when I spoke to them towing was on my hit list so they recommended that particular TC. I did say the motor was mildly built, maybe just a bit more than mild,,, :)

Are you saying the Patriot sidepipe muffler has an 1 3/4" ID?
I was looking at these.
http://www.jegs.com/i/Patriot-Exhaust/7 ... 0/10002/-1
I've not seen them so it may be worthwhile to order at Autozone and simply not buy them if they are crap when I get a chance to see them first hand.
'93 Safari shorty, 350 swap
'05 Astro AWD, lifted, 6 liter, cammed, ported and programmed for fast.
'69 G10, straight 6, 3 onatree, jumped at me when I had a pocketful of cash looking for a spare astro. :)
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Re: Exhaust question

Post by Mmusicman »

WoodButcher wrote:Are you saying the Patriot sidepipe muffler has an 1 3/4" ID?
I was looking at these.
http://www.jegs.com/i/Patriot-Exhaust/7 ... 0/10002/-1
I've not seen them so it may be worthwhile to order at Autozone and simply not buy them if they are crap when I get a chance to see them first hand.
Everyone now seems to sell the same brand side-pipes... apparently the last of the side-pipe manufacturers. Regarding the muffler ID, I can not say for certain about the Patriots since I bought my side pipes roughly 20 years ago (under another name brand). But they "look" identical ... so I'm assuming they probably are the same, just under a different name.

The "inlet" size has NOTHING to do with the actual muffler ID (which is contained withing the side-pipe). Back when I bought mine I noted how small the muffler ID actually was, and back then it was suggested that it was roughly 1 3/4" ID.

I do know one thing.... they SOUNDED GREAT! They had that perfect deep mellow glass-pack sound! Maybe worth a small HP top end trade-off!

They are NOT high-flowing performance mufflers. You would need to determine what is important to you. HP loss is most typically at the high end of the rpm range anyway... lower end torque may be less affected. It's not likely you will ever find any true and accurate graphs or charts. If you use the pipes as is... the performance loss would most likely be negligible, and basically offset by the boost of headers anyway which will still benefit you. If that's not good enough, the other option might be to try what I suggested using performance mufflers rerouted back to the side-pipes (with baffles/mufflers removed) used like tailpipes.
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2000 Chevy Astro LS AWD | 31" LT265/70R17 Tires | 8" LIFT | 10" TOTAL
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Re: Exhaust question

Post by Mr_Roboto »

Mmusicman wrote:My V8 has a "medium performance" high-torque/hp cam... which is pretty rough/choppy at idle. Add A/C and I have to keep the idle somewhat higher than I want (in neutral), and sometimes have to take it out of gear at lights to keep it running, while under load. A higher stall (I'm estimating 2400rpm) will address this condition.. as I have used them before. They give you a hell of a launch too... but I already smoke my tires so that won't matter much. I also need to be sure this performance torque converter has lock-up. They start getting a little pricey.

You're 700R4 with stock converter will be excellent behind a mild V8! Assuming it is a later model 700R4, it already has some nice strength improvements over the earlier models. The 700R4 was run from factory behind V8's in earlier full size vans and truck anyways.

You may have an issue with the torque-converter bolt pattern bolting up to an older model flex-plate. My '92 700R4 converter would not bolt up to the stock flexplate of a 70's model V8. Fortunately, I also had an 80's model flex-plate (with dual patterns) that matched up perfectly! Don't get burned on this one... be sure to see if they match up... BEFORE installation.

Poly motor-mounts? I don't see any reason why not! I had also considered it. But be aware because they are so firm, they might cause a little more harshness with vibration... I'm not sure. I've never used them, but I'm sure you could research them. In my case I bought very expensive "factory dealer" mounts (about $60) compared to $5 cheap ones I already had new (and wound up throwing them away). I didn't want mounts that could potentially come apart 6 months down the road... for any price!

Here is a quick little "launch" video of me "parking" in the garage... lol
https://www.youtube.com/watch?v=rXyS6edaAUY
[youtube]rXyS6edaAUY[/youtube]
May I offer a suggestion? You have a carb, right? Get a solenoid that's normally closed, run it to a vacuum port and then run it up into the air cleaner so that the air is filtered. Turn the solenoid on when you've got your AC on. Should let you drop the idle considerably at that point.

Besides that, just wanted to say I have very serious doubts of 'vette headers fitting an Astro. They dump out pretty well where the subframe mid section is. Sorry.
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