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5.7 swap: help please

Posted: Fri Jun 27, 2008 12:33 pm
by gabequest
Yo Folks: new here and need some advice. My 98 has a rod knock and you know what that means...V8! I wanna swap in a 5.7 vortec. Two problems: money and I'm an idiot. Credit card solves the first prob and a GM master technician is gonna solve the second. This means we gotta get it right the first time, because I will have a hard time trouble shooting on my own...I need reliability. I have to get my parts in order so he can do the swap. Does anyone have a parts list? I'm hoping to find a complete motor and need to know about radiator, trans cooler, exhaust manifold etc. I've already got the computer and wire harness figured out.

please and thanks

Re: 5.7 swap: help please

Posted: Fri Jun 27, 2008 1:56 pm
by Rebel
Welcome to ASV's. Lots of info here on this type swap and you'll get a few who'll reply with the help you'll need. Wish I could but my old school carb swap won't help you at all.
Good luck.

Re: 5.7 swap: help please

Posted: Sun Jun 29, 2008 5:47 pm
by zook94
In all but the hottest climates in the states, the stock radiator will cool a V8 fine. Ditching the factory engine driven fan for an electric fan with shroud, like those built by ford for use in just about everything, from Taurus to Crown Vic. That will gain you some room in front of the engine, and less crap to fiddle with cutting the factory shroud to fit. The transmission cooler, any monkey with a flat blade screwdriver can install one, buy the largest one you can get, the cooler your 4L60E will thank you. For the exhaust, use the Vortech 5.7 pickup manifolds, and get at least 6 inches of the crossover pipe left attached to the manifolds. The exhaust shop will thank you, as all they will have to do, is trim the ends to length, and weld the new stubs to the factory Astro exhaust. I have done this with the last 3 swaps that I have done, and the guys at Midas love quick easy work. Some people slot the holes in the exhaust flange, and use washers to keep things from falling apart, but I find that a proper fit works much better.

You didn't mention motor mounts, have you procured the correct ones? You didn't indicate whether your van is 2wd or AWD, and the mounts are very different.

Re: 5.7 swap: help please

Posted: Thu Jul 03, 2008 6:13 am
by gabequest
Hey thanks! I can see why you said in my other post to just add that info in this one...but I am a simple man and tend to post when thoughts pop in my mind...woops. Mine is an AWD (4WD now).

As with the other thread...I've got mounts coming and probably oil pan from JTR. I will be in Tucson late summer, so may want to go with a stronger radiator. Would simply using the radiator from the donor work out? The guy will sell it for $100. Do I need any special hosing for the taurus rad? I'm pretty sure JTR sells some hosing to fit the 4.3 rad. May go that route, but could use some more advice....what kind of temps are you speaking of when you say "all but the hottest climates"?

thanks again!

Re: 5.7 swap: help please

Posted: Thu Jul 03, 2008 9:05 am
by phr1$k37

gabequest - please document your swap :p Please oh!?

Re: 5.7 swap: help please

Posted: Thu Jul 03, 2008 11:49 am
by gabequest
Would love to document for ya, but I suck at big projects an am having a chevy guy put it in for me. sorry bout that!

Re: 5.7 swap: help please

Posted: Thu Jul 03, 2008 12:57 pm
by phr1$k37
gabequest wrote:Would love to document for ya, but I suck at big projects an am having a chevy guy put it in for me. sorry bout that!

LOL well hey anything helps!!! I have an 97 and am thinking if anything happens to my current motor ... V8 time.

Re: 5.7 swap: help please

Posted: Thu Jul 03, 2008 9:48 pm
by gabequest
Well: I'll certainly get a list together once every thing is in and tested. Gotta give back a little. Folks on this site have made all this possible for me!

Re: 5.7 swap: help please

Posted: Fri Jul 04, 2008 8:23 am
by mdmead
zook94 wrote: For the exhaust, use the Vortech 5.7 pickup manifolds, and get at least 6 inches of the crossover pipe left attached to the manifolds.
Now that we know this is an AWD van, will these manifolds still work? I was under the impression that they wouldn't in an AWD.

Regarding the radiator, several have used a heavy duty replacement from Auto Zone. "Heat Buster" I believe. It is a heavy duty replacement (for the 4.3L Astro/Safari) that works well with the V-8. (Combine this radiator with the electric fans from a Taurus as mentioned.)

Re: 5.7 swap: help please

Posted: Fri Jul 04, 2008 1:31 pm
by gabequest
Thanks! The manifolds are still on the engine: from a suburban. I'll have to have a shop weld up the y pipe. Are these manifolds too big or something like that? That damn oil pan is my real crux. Prob will have it mocked up when the guy goes to put the motor in, then have it fabbed.

Also, probably just gonna use the stock rad w dual 12 in JEGS electrics, and just order a Tru-Cool (the 11x11xsomething or other). It is my understanding this should work out...unless you already know it doesnt.

gabe

Re: 5.7 swap: help please

Posted: Sat Jul 05, 2008 9:35 am
by Rockwerx
Nice bumpers. Now you can go bush wacking! Where did you get them?

I would run a pickup rad in your van. They are wider and only require making some mounts, relocate a couple of things and a bit of fabrication to make them work. Add to that your new twin fans you will be set to hit the desert on the hottest of days. Good luck with your swap!

Re: 5.7 swap: help please

Posted: Sat Jul 05, 2008 9:50 am
by gabequest
I had the bumpers made by a company in Montrose, CO called Rockworks. The rear cost $600 and the front was near $800. Pricey...but I love em'. And I get multiple people daily inquiring about the van...good conversation starter.

On the radiator...As per some others' advice, I'll be running the stock rad with Flx-a-lite twins pulling 4600 cfm and the tru-cool trans cooler. This should work even in the desert...right? [-o<

Re: 5.7 swap: help please

Posted: Sat Jul 05, 2008 11:26 am
by canadavan
I seem to recall that the AWD vans require headers, that the truck manifolds won't fit.

Re: 5.7 swap: help please

Posted: Sun Jul 06, 2008 5:59 pm
by zook94
The Taurus fan is a single, and it has the shroud built right in. I would definitely steer clear of aftermarket electric fans, as air only gets forced through the fan footprint, and about 60% of the radiator is ineffective unless you are driving at highway speeds. The Autozone heatbuster is a 3 core radiator, plenty of cooling even for a big block engine. Swapping in a different radiator is going to take fabrication, and your GM tech buddy is probably going to pitch fits about having non bolt-in parts.

I have tried with every configuration to use the factory GM shroud, and no matter how much chopping and clearancing you do, it still works poorly at best. Just go to an auto wreckers, and spend the $20 on a Taurus fan. It has 2 speeds, and with the proper wiring, can seamlessly go from low to high when temperatures get up there, and as a plus, they pull enough air to draw through the transmission cooler, the A/C, and the radiator, with plenty of oomph to push heat through the engine compartment, keeping the engine itself cool.

Re: 5.7 swap: help please

Posted: Sun Jul 06, 2008 6:48 pm
by gabequest
Well...as per some of you folks' advice and I guess...against some others'...I'm gonna try the stock rad w/dual Flx-A-Lite's pullin 4600cfm.

Now...different topic...but are the 5.7's exhaust manifolds gonna fit? I got 2 inches of body lift.