How much will headers open up my 305 (stock)? if so what kind. then if i got some cutouts how much hp could i be expectin?

 

o yea its TBI w/ a T5 (if that makes any difference)

 

i put the shortys on my 350 tpi and dropped about .5 seconds off my 8th mile times. it woke it up A LOT! should do the same for your 305. if you haven't done anything radical, i would do the short tubed headers.

 

i dont know if it would be different on a TBI,but i know on a TPI i think headers give u about 15-20 HP. so i would imagin somewhere close to that

 

What about headers on a '92 350 TPI ? Does it mess with the computer ? Do I have to burn another chip ? Do I need AFPR ?

 

if u can fit them get LTs not shortys, u will get much more power outta them

 

Headers are very worth-while on the Lo3. The manifolds are absolutely terrible. I went with the Hooker 2055's for emissions cars and Im pretty happy with them. They're like $350 from Summit. SLP - while I've never had expirence with them - are generally regarded as the best. The MAC ones look real good, but I couldnt find a set that I wouldnt have to get my arm + leg for.

Just make sure you get a 3" y-pipe and when you do exhaust do 3" all the way back. Companies like to sell smaller parts for tbi cars but you want 3".

 

you may have to modify the headers some to fit the O2 sensor. (ie, drill a new hole)

 

If you don't plan to mod it further, then get something like SLP 1 5/8 headers. It won't "mess" with the computer. You will see benifits to having a new chip burnt. I persnally recommend www.fasterproms.com for this sort of work. $350 to buy in and $150 for future tweaks. They will send you a rough burn and you install it and run it and take readings and they will send you another and another By 3rd time, it should be nuts on. I don't care much for AFPR because it raises fuel pressure across the board instead of at the place it needs it. While they are burning your chip, they will compensate for the lack of fuel at some points and over richness at others.