I've got a 64 300 4-barrell Skylark. It is mostly stock (rebuilt) with 10.25:1 compression aluminum heads and intake. It has a set of full length POSTON headers with a JET-HOT coating. The headers look great but have been a problem since day 1, noisy at best and they start to leak after a couple months. I'm thinking of going back to the cast iron logs. Being a 64 there is no heat riser and the logs look pretty efficient as far as manifolds go. Anyone have any opinion on this? How much hp can I expect to lose? Also do you use gaskets with the cast iron manifolds? I'm pretty sure the manifolds didn't have gaskets on when I removed them 10 years ago .... and they didn;t leak either.
Find a quality gasket & constantly retorque the bolts.Or i'm sure they would sell quite fast in parts for sale:Brow:
You might try the Rover stainless MLS exhaust gaskets. They are expensive, and the beading is going to be inside the port a little bit because they are sized for the Rover (215 Buick) ports which are smaller, but they just might do the trick anyway. My headers have big ports because when I built them I planned to go bigger and am now in the process of doing just that. I used them on the 215 and the Rover gaskets were the only thing I found that would make a reliable seal. I haven't tried them yet with the 300 heads ('64). If you have the iron heads I guess the exhaust ports may be larger still. But, there are at least a couple of gasket companies I would contact about either MLS or copper exhaust gaskets. SCE will make copper exhaust gaskets for you at a reasonable price. I don't know how much yet but that's one option I'm considering, and from what I've heard they do a real good job of sealing headers, but again that's heresay. Cometic makes mls exhaust gaskets for the V6 in 2 sizes for ported and unported engines. I have no details on them but if they can be had in stainless and are the right size they would be an excellent choice because the stainless ones never lose their springiness in the bead area. V6 ports should be the same as the 300/340, or extremely close. HTH Jim
http://www.v8buick.com/showthread.php?t=169781&highlight=headers+electrajim Header leak info, just 1 thread anyway. ElectraJim
No leaks at all:TU: ... mainly because the flange is 7/16 thick, before the ceramic coating. Do a scan for Sanderson (here in this SBT section) and you should find the pixs that I posted. Since then I put about 4K miles on them before I tore the engine down for rebuild.
Have you tried 'em? There isn't an early SBB listing in their catalog and the V6 is a one piece for 3 ports. What the heck is "flexible graphite" anyway? I'd love to hear some real world results. Jim
Nope. Havn't tried them. I'm still on the set that came with my headers. I don't know who makes the gaskets I have in service. I'm curious on the "real world results" too....but not until mine fail. uzzled: ElectraJim
