Well guys i did it today..on a 305 though..1 5/8 SLP headers gained me 7 RWHP and 3ftlbs of torque... but the overall torque and horspower curves started at a high rate from the last time.
So I think they are worth it to me! just thought I would fill you guys in..

 

thats it. damn

do you have any track times before and after the headers.

 

7rwhp, that's it??

 

do you have a catback? Maybe the 2 and 1/2 inch piping is hurting the header improvement?

 

Bet the heddmans aren't lookin so bad now eh?

I knocked 1/2 a second off my ET with heddman 1 5/8" shorties, Y-pipe & cut-out. More importantly they did not cost me $900.

 

my set of flowtech headers cost $194 dollars with tax and i know they picked up more than 7 hp. plus i was able to sit down on a wooden chair comfortably after my purchase, as opposed to you who still has to deal with the uncomfort of having been violated by SLP.

.........sorry.....i know they are nice units... it just seems that these particular units are way to expensive for what they do (or lack of what they do)

 

my hedmans are modified though, so they flow more then yours

 

well i lost 3/10's and gained 3mph with my SLP 1 3/4 headers on a 305 so they cant be that bad.

 

15.0 before headers 14.7 after with 2.4 60foot times and trap speed of 96mph...

 

In all fairness, you did start with TPI manifolds which are almost as good as some low line headers. I went straight from LG4 manifolds (only suitable for anchoring small watercraft) to Hedman 1 5/8".

 

Very true...

 

how much did it cost you total to do the header install?
also how long? and modification if any?

 

$900CDN.. about 7 hours... need a mig welder to weld the y pipe to the cats... sawzall to cut the pipe..... the only modification was a half inch 90degree elbow to hook up the AIR tubes... I get alot og guys say nice plumb job..!! hahaha but hey it works... if you get hookers there AIR tubes are on the right angle..

 

Damn! Get some tires on that car and run some low 14's.

I picked up almost 3 tenths after putting on my SLP 1 5/8" headers.

 

I am looking for them as we speak

 

Check out my sig for my dyno results with SLP headers, Random Tech exhaust, underdrive pulleys and AFPR. The AFPR helped A LOT with the torque. I adjusted it at the dyno and made big increases while at the dyno.

 

I don't think 7hp is too shabby on a 305. A 305 doesn't exactly move as much air as a 350.