Chevy & GMC Vans

yeah it's me again...more questions! I've got a 350 chevy in Golden Girl now, but she's still got stock manifolds (ugh), can you get an "off the shelf" set of headers that will work in an 89 Safari??

cheers!
Diva

I think the most popular headers are the Hedman 68600.

Skip is correct,,,that is the number. I installed the header plugs to gain a little more room but still had to dimple on the inside of number 6 I think it was, for clearence. Also makes it a little easier to install and remove the plugs after headers are installed if you'll cut about 1/2" off the plug socket. Good luck on the install,,should be interesting. Never put a set on after 350 installed but you'll get er.

I've got a follow-on question regarding headers.

I'm about to upgrade my 1992 LT EXT from the L98 TPI 355 is has now to a LT1-based 396. The van had long-tube headers before from a 2d-gen Camaro, although I forgot the model number of the headers long ago. In any case, I want to upgrade to 1-3/4 inch tubes, and ceramic coat them while I'm at it.

Will the same headers that fit on the original SBC also fit on the LT1? Are there any specific recommendations on long-tube LT1 1-3/4" primary-tube ceramic-coated headers? The LT1 heads are aluminum (aftermarket, fashioned after LT1 heads), if that matters. It will have a T56 6-speed as well.

Thanks in advance.....Jim

I have Doug Thorley tri-y headers on my 350 for building towing torque, but they are not cheap so get them from a swapmeet like I did.

I've got the headers Skip mentioned,,never had any leaks after installing the aluminum drop in gaskets. One thing I'd like to advise is get the coated headers or stainless if you plan on keeping the ride for long.
Check with Skip White on his stainless for early Camero. Great folks to deal with.

http://shop.ebay.com/skipwhite/m.html?_ ... m14&_pgn=3

Just checked his site,,,even better deal on this dist. I bought from him a few years back. Unreal price.

http://cgi.ebay.com/ebaymotors/CHEVY-EL ... ccessories

I suggest the Dynatech Header System. This header work with both aftermarket and factory cat-back exhaust systems. It will help improve exhaust flow and hp & torque.

you will need to shave down the left side engine mount slightly to allow the headers to clear without having to pound a dent into the header. If you are lucky they didn't use the ebay mounts and they might already be shaved. There is nothing wrong with the ebay mounts they just need a slight trim to fit headers.

Little redundant, but as a 68600 user I can verify the following:

1)You will need to trim the mount if it's an ebay mount. about 1/4 inch of steel needs to go.
2)The plug clearance on them is TIGHT. Very tight. I used fiberglass supercomp style booties for my plug wires to keep them from getting the snot burned out of them. Dimpling some tubes may help some but the plugs I had were pretty much touching. Straight plug "416" 305 TPI heads.
3)If you can find some "D" port headers are probably preferred. LT-1s with aluminum heads used D ports I believe. You may be able to grind a set of stockers to work better with them. Otherwise with the combination you may be forced to do something custom. I doubt there are that many headers out there made for a second gen Camaro with D port heads and a T56. Just saying expect to modify something at some point or get/make custom.
4)If I remember correctly LT-1 B-car manifolds are really odd shaped. Don't expect them to clearance right I think they might hit the dog house. Not 100% on that but keep it in mind and look before you buy.

My next set of headers are probably going to be MIGed by me. I have the bends and flanges here, and I'm not really aware of anyone that makes a header for an Astro that is twin turbo compatible.

That 4" stroke LT1 should be a ton of fun. I wouldn't want to go toe to toe with it!

The "Second time" I used the stock iron 5.7L Vortec headers. I port matched them. Otherwise with the "conversion headers" people use you cant change the plugs and the thin tube headers kept cracking on me. I had to take them out and reweld them multiple times. So i said forget it. I had a machine shop shave the pass side vortec headers for clearance because they were hitting the subframe a tad. They took off .5inch from the mount at a slight angle to further tilt the headers away from the subframe. No more exhaust problems.

http://www.ancc.cc/chris/astro/exhaust

Some of the local stock car classes are restricted to cast iron headers.I saw a company that uses something that looks like a thick silly puddly with a abrasive in it.They pressure force it threw the headers to open them up and kind of port them.I saw it and thought it was pretty slick.

1Gary wrote:Some of the local stock car classes are restricted to cast iron headers.I saw a company that uses something that looks like a thick silly puddly with a abrasive in it.They pressure force it threw the headers to open them up and kind of port them.I saw it and thought it was pretty slick.

Extrusion porting is what the process is called and it is awsome.