I have recently completed the build of a 11.2:1 compression 383. It should put 400-420 to the rear wheels NA and plans for a 150 shot are in the future. The car is on the HEAVY side (4444lbs last time out) so the more torque the better. I am looking at either a 1-5/8 Tri-Y header (midlength) or a 1-3/4 long tube header. The Tri-Y has more clearance for plugs/wires/bolt access than the long tubes but supposidly the long tubes should make more power.

Is it worth the additional hassle of the long tubes because of the power gained moving to a larger header or would the outputs be within a few HP of eachother? I have been playing both sides in my mind but have not been able to decide. I am just looking for advise and I am sure this has been gone over thousands of times and if so I am sorry, but here is 1 more for reference.

Thanks for your help,
TOM B

 

Plug access really isnt that bad with long tubes. I've had an LT1 with mid lengths, and an LT1 with long tubes - both were about the same for plug access.

Go with the long tubes - they make more power and are about the same cost. Down the road, you will be glad you did.

 

Might want to mention the year, model, and engine info for the car. Sounds like it may be a B-Body.

 

It's definitely a pig if not.

It's personally preference. I'm running shortys because my ride height (~2" drop) necessitated keeping my stock Y pipe.

With your power output, I'd say give it as much exhaust as you can and let it breath. It's not gonna be that much harder to install, and you only change your plugs/wires maybe every 50,000 miles.

 

You are correct - it is a 1996 Impala SS LT1 w/OBD1 conversion PCM and T56 transmission. In the past I have stated "Impala" and not gotten much feedback so I kind of left it out intensionally - no biggie. I have decided to go ahead and get the long tubes. I agree with what you said in that I won't regret it later down the road as my HP goals increase.

Thanks guys,
TOM B

 

A little extra work/$ now will pay off down the road.

That being said, I only suggest shorty/mids to people who are:
A) Stuck with emissions/ride height requirements
or
B) Just doing a few bolt-ons on the car and don't want to spend the $$$ for a few extra HP. With your car already making 400rwhp, and 480rwhp+ on the bottle, I think you'd regret not going with the best exhaust flow you can get.

That being said, nothing wrong with owning a B-Body. It's just nice to know because if we suggest a particular header, it might not work on your car.

Good luck with your header swap.