I only think LT headers are worth the money. I have ceramic coated on mine, and ran them on my Chevelle when I had it, and also on my Camaro when I had that. Could tell a difference in all. Like it was stated. Make sure to retighten your bolts or yes, it will start to leak. Probably something your "hotrodder" friend didn't do. Only problem I had with mine is that I had to trim a bolt on the left side inner fender well to fit it. But I have a 67 with a 351W so it might fit with no problem in yours.

 

Maybe check out Hooker. I have Hooker Competition headers on my cleveland that are ceramic coated. I have an automatic C6, but I think they said that they would fit a manual as well.

 

If you have 10.7:1 compression in a 4v cleveland you definitely would benefit from headers and 2.5" dual exhaust with a "tuned" crossover. (Tuned crossover means installed at the proper location which would be the hottest point in the exhaust, usually within 3-4 feet of the back of the engine, and it varies for every engine)

Unfortunately a 4v cleveland has cyl. heads that are way too big to ever get a lot of bottom-end torque anyway. So don't choke it down either with too small of exhaust losing power at the higher rpm range where it likes to run. They do have restrictor plates that can be installed in the intake, and some machine-shops can fill the exhaust ports by welding or properly using ceramic. The best bet is to get a set of 2V heads or Aussie heads and go that route. Either way in my experiences clevelands like high revv's, good headers, and 2.5" exhaust with a tuned crossover tube. Good luck.

 

Thanks for the info BWK.
The Aussie heads would definatly be the way to go if my 4v heads were tired, but the engine was just rebuilt. Besides, my "internal accountant" is having trouble cause the price is about 1/3 of the way towards a new 400hp Windsor crate motor.

Back to the headers, I noticed several cos have shorty headers. They would seem to help with fitment issues. Is there a performance gain with shortys vs the stock iron?

 

You're welcome for the info, that's just my experience with the Clevelands. YES, you would benefit from a good quality shorty header and most of those dump directly into a 2 1/2" pipe flange which would be perfect. I personally like long-tube headers for their sound and scavenging abilities but shorties would work for a mild performance engine. The problem with stock manifolds is a total lack of scavenging, casting boogers, and jagged pieces of cast-iron on the inside that you can't see or even get to to remove. The largest passage I've ever seen inside of one is like 2" on a real nice and ported-out hi-po manifold but even then the runners were too short for consistent flow. They just suck, plain and simple, and they really mess up your exhaust pulses and cause too much back-pressure and firing order interference in the exhaust. Unless you're building an all-original Concourse vehicle, use em as boat anchors. Get rid of em.

I went from stock manifolds and 2" pipe on a mildly built 302 to full-length headers and 2.5" pipe and holy crap what a difference! No comparison. You may also find out that with a little tuning you will gain some torque, definitely mid-range torque from a good flowing exhaust.