Biulding new 15 degree engine for my 85.Headers are turning into a real issue.Companies like Stahl offer drag race versions, but worry about clearance.Ican get pieces and weld my own.EG. Stahl and American racing.Anyone here being playing with 15 or 18 degree stuff.Tube size min. 7/8" primarys.Thanks . John.

 

Keep an eye on this thread:

http://forums.corvetteforum.com/c4-t...ree-heads.html

You and the OP may be able to brainstorm. I think he is leaning towards making his own though.

 

I had my 15 degree headers made by Dawson Racing Headers, the passenger side had no problems, the driver side was touching the steering rod a bit. I marked the spot and used a big impact socket and a baby sledge hammer to make a concave shape at the area where it was touching. Problems solved, Dawson would have modified it for me but, I did not want to pay for the shipping. Do not get a 3.5 inch collector because the oxygen sensor will be a tight fit. Hope this help.
How about some info on your combination?

 

You guys have been great.I'VE been trying to get in contact with dawson racing headers after one member suggested it.His heads are -12 brodex 15 degree,which are slightly different in port configuration.bolt patern different and cyi,1,7,2,8 exhaust are in stock location on his.GM 15x has those ports spread out slightly further.The exhaust ports on cyi,3,5,4,6, are spread about the same.Dawson racing might be able to help.I'm sorry, i have'nt given you more info on my biuld.I've been busy.Where to start.Well the valves are titanium,the rockers are jessel race sieries 1.8 intake & 1.65 exhaust.Right now the heads are on the cnc machine.combustion cambers are finished 36cc.The exhaust ports & bowls are done.The intake openings are cut.Whats left ? The borillium copper seat and guides,intake port & bowl work left,then the flow bench.The block is little M ,eagle h-beam 6"rods ,scatt super light steel crank.Have'nt sent specs to comp cams to grind cam yet ,but have the jessel big bore off set lifters.The pistons , my friend has ideas about them .I'll let you know when do.THATS GOOD FOR NOW.Oh ya.The car is an 85 red with 315/35r 17s on all 4s.Iused to race auto cross for years but out of it in 2003.Time to get back into it.WHAT DO YOU THINK?BY FOR NOW JOHN.

 

Still trying to get ahold of dawson.My emails keep getting sent back,can't reach.

 

John
The Brodix -12 uses a regular old spread port bolt pattern, which is the same as a Stahl bolt pattern. Nothing special and very easy to find flanges for.

You can get everything you need to build or modify headers to fit from here.

http://www.spdexhaust.com/index.html

A few people have taken common 23* headers and cut/weld - swapped the flanges.

Finally ARH probally could build what you needed. They make the nicest 23* headers aviliable for the C4 Corvette.

http://americanracingheader.reachloc..._id=5437795169

Will