[jameskirk1]

I've had my swap done for full year now, and the mini-mill is still running EXTREMELY strong...I'm using the Hedman swap headers (which I've found are pretty much the "norm") with 1 1/2 primaries and 2 1/2" collectors...They seem to work great with this small displacement motor...However, the next mill in the works should hopefully put out around 425hp...I'm planning right now for a 355; but might "crank out" to a 383...My question is this:

If I keep the existing headers, do you think they will choke off some horsepower? How big a difference would 1 5/8" primary or even 1 3/4" primary headers (probably from Sanderson) make on an engine in this horsepower range? I'm planning for primarily street running, with limited strip use...

In addition: Is anyone out there using these larger primary size headers with the stock collumn shifter and a 700R4? If so are there any additional clearance problems?

Hopefully some experienced tuners/racers have some helpful insight in this area... THANKS!!! :thumbup:

 

[dumpeds10]

the heddman header should be fine my buddy has them on his truck and he is putting out over 400 hp so you should be fine with the headers that you have
are they shorty or full lenght hedders

 

[jameskirk1]

Thanks for your reply bro...

They are the shorties...

I wonder if your buddy could be making 425hp if he had the larger primaries? How much a difference from 1 1/2" primaries vs. 1 5/8" horsepower wise?

 

[Bad-S]

yea i was actually gonna ask that same question...im pullin my 355 apart and changing some stuff around and im looking at 400-425 range and have 1.5 2.5 hedmans... thought of goin to sanderson 1 3/4 but dont want to if dont have to

 

[dumpeds10]

im not sure how much more power you would get maybe 15 to 20 but it also depends on the exhaust to if you run a big primary and a small tube exhaust you kinda defeteing the purpose of the bigger headers

 

[jameskirk1]

Thanks for the replies dumped...

If I decide to change the headers out I'm sure I'll upscale the exhaust system as well...Right now I've got a 2 1/4 dual setup with some killer flowing turbo mufflers...But I bet a 2 1/2" or even 3" system would be even better with a higher horse engine...

Anyone else with have experience with the available header sizes for a SBC? S-10 or not?

 

[hellbents10]

My Grandpa has sanderson 1 3/4 w/ 3" collector and dual 3" with h-pipe and dynomax ultra flows. Mandrel bent all the way to the roll pan. Sounds really good and performs good too.

 

[jameskirk1]

Where did he find the room to cram in an H-pipe??....OMG

 

[rick]

hedders

The 1.1/2 headers will make good power if you don,t want to spend the cash. You won,t need anything more than 1.5/8 . I have the 1,3/4 sandersons only because of the huge exhaust ports on the 200cc pro topline heads.A good 2.5 inch dual system will support the power range that you want and not give you any problems with running the pipe. Make sure to use an H-pipe or better yet an x pipe. I made myself an x-pipe,just because they cut down noise in the cab.If you do deside that bigger is better and go with the 1,3/4 models make sure you use straight plug heads.

 

[BlazinLow]

I used to have the shorty hedman and then when i beefed up my motor more I went with the long tubes with the 1 5/8 primaries. You should be fine with the 700r and column shifter.

 

[jameskirk1]

Thanks for all the replies...I think ol' rick just answered my question...THANKS BRO!!! (Btw, If any of you guys need some sound engine/hot rodding advice, search rick's posts...I know I have...)

THANKS

 

[baddazzlt1]

I bought both the headmen long tube and short tube heades when i started building my engine. When I got it on the dyno it made 35 more hp with the long tubes. We also think it had alot to do with the compression and my cam. we put both headers on a not so built engine and the shorty headers made more power.

 

[jameskirk1]

Thanks for the reply man!!!

What horsepower range was the engine with the full length headers? Same question for the one with the shorties?

 

[baddazzlt1]

the full length headers where on an engine the made 485hp(355ci) and the short tube if i remeber rigth was around the 300-330hp range(355ci).

 

[jameskirk1]

Thanks everybody for the good responses....