I got some custom made 1 3/4 long tube headers and a full exhaust from a friend for $250. I want to know how much will I gain from these headers on my 305. I know the 305 is supposed to 1 5/8 but I plan on a ZZ4 crate motor so I got these headers plus they were a bargain. Will they end up just hurting the engine or will it gain some? What if I put in the true dual setup any pros from changing from single to true dual with H-pipe? The headers will fit perfect since my friend had them made for his 3rd gen Z28 drag car which ran 10s Any help will be appreciated.

 

thats a lot of questions and I really can't answer all of them....but headers will give you more horses no matter what, long tubes will usually leave you with some decent torque too

 

Well I am scatching the true dual because it will be too hard to get it to pass SMOG. The headers are going to have to be converted to AIR but I want to know what kind of gain can I expect from them?

 

I can tell you what my setup got me. I already had the flowmaster cat back, but when we added the headers, y, and cat delete, I picked up a major SOTP difference along with .6 and 4-5mph in the 1/4. You'll notice, beleive me!

 

Wow .6 that's a big increase These are long tube headers so they should help my bottom end as well. Now I just need to save to have them AIR converted and installed. Would .6 increase be realistic for the 305 TPI?

 

I'd say its certainly possible. I mean, your car should be making more HP than mine I'd assume, so, removing a bottleneck from a car with more power should make as much if not more diff. than a car making less power. Unless TPI cars have better flowing manifolds, which they might, I dunno for sure. No matter what, you'll feel/hear the difference.

 

Yes you will feel the difference, but you might lose a little torque on the low end, but it will make up for it on the high rpms. Im not sure about long tubes though. You might be able to make the torque back up with them.

 

I've felt the diff. at all RPMs from mine, but it could be cause my convertor was blown and sometimes the chunks rattling around clogged itself I think. Probably why I got such a dramatic difference.