header mods?

[montess408]

hey guys do you think that i can buy a set of headers made for a 2.8L S-10 and make them fit a 3.1L mpfi in a fwd car or is the iron head/aluminum head thing going to stop this idea again ?not sure if the exhaust ports line up or not ?

[Ortie666]

Juss get/make a flange that will fit a set of aluminum heads, and weld it to the existing tubes of the 2.8 headers, and you should be green flag for having them fit to the engine, but I would think that the headers would be no were neer fitting into the car properly, but its worth a shot I guess.. You could just make a full set of headers witch isnt rocket science, there is probably over a dozen people on here who have done it already. I bet one of them could help you.

[montess408]

so you dont think that the 2.8L S-10 flange will work?

[Guest]

so you dont think that the 2.8L S-10 flange will work?

It won't, the bolt spacing is different.

The rest if the header is COMPLETLY wrong to fit a FWD chassis.

[sharkey]

i wouldnt say completly wrong. the headers on my cavy were 2wd s10 headers at one point. i picked them up brand new cheaper than i could get collectors and flanges. i basicly took them and chopped the flange off a couple inches from the head, positioned the collector (still with most of the tubing on them) and made the rest of the tubes to fit it from u-bends. it actualy worked out very well. they are not equal length, but i wasnt to concerned about that. they ended up being 22" primaries, wich was fine for what i wanted.

and just to confirm, no the s10 header flange will not bolt to an aluminum head. my motor uses cast iron heads, same as an s10.

[montess408]

oh well back to square 1 i guess, by the way if i was to run duals on my car would i have to use 2 oxygen sensors ?

[Superdave]

the Iron head 2.8 flanges aren't that much different.. I used them on my 3400 so i know damn well they'll go on a 3.1.

you need to ream out the mount holes a little. Just clamp on a gasket and use a dye grinder to match it up.

[sharkey]

i run true dual exaust on my car with 1 o2 sensor mounted in the collector of the rear header. i did find that due to the o2 sensor now being over 20" from the head that it cooled down to much after idling for 30 seconds. i replaced the 1 wire sensor with a 4 wire headed o2 sensor (i beleive we have instructions somewere on this site for wiring it up). however, i now run a wideband o2 system on my car for tuning.

[XLR8ING]

I did the S10 header rework for my car. The front was basically untouched except the bolt hole spacing is different. The bolt holes have to be stretched.
The back had to be completely cut, fitted and welded little bits at a time. Took over a week of work to do.
But the headers only cost me $100 CDN brand new.
Here's a picture of what they looked like when I took them off the car.

[Ortie666]

WOW, man thats some mad swap shit!! Props for trying somthing like that and making it work!!

[XLR8ING]

Thanks!

[geoffinbc]

If you guys want flanges I have them. That way you get a nice thick flange ready to bolt on. Just cut off the header flange that is on there now. Also I have them for Gen III heads with D port openings.

[97cutlas$upreme]

i know this might sound stupid but the 3800 headers seem to have the same bends like on the 3100 could you change the flanges and make them work? just out of curiosity

[Superdave]

i know this might sound stupid but the 3800 headers seem to have the same bends like on the 3100 could you change the flanges and make them work? just out of curiosity

not quite, the 3800 has equal spacing between the ports whereas the '660 has 2 that are closer together...


3800 header:




3400 ('660) header:

[sharkey]

while we are at it, here are my shorty headers i made for my car