Fellas, having a bit of drama with the stock exhaust manifold.... I have recently had bolts snap off inside the exhaust manifold and I cannot for the life of me get them out ! The easy out is now also stuck in the thread. I was looking at getting new headers anyway but I have been getting mixed advice. Should I stick with the factory manifold or start fresh with a set of headers? There is minor performance improvements on the engine - edelbrock carby & manifold & suspected mild cam. Appreciate the help.
Remove the cylinder head and bring it to a machine shop to have the bolt and tool remains removed. Yes I would do headers and Remflex gaskets as they will never leak or require re tighten the bolts.
I’d do manifolds. The factory assembly was good for 50+ years; do then them right and you’ll get that again. And not sure an Edelbrock carb is a ‘performance improvement’. A properly set up Qjet is the best carb you can run on anything this side of an 11 second car. Patrick
Hi Sean, thanks for the reply - I have been reading around and hear TA shortys are the go for my 68 riv I’m in Australia so I have to choose wisely - no returns
TA shorty's are the ONLY headers that fit our Rivs. It's a no brainer just order them and a set of the Remflex gaskets like mentioned before and all your headaches go away, well for that scenario anyways lol. Ditch the edelbrock carb and order a fully tuned for your combo Qjet unit from Ken at Everyday performance, here on the board. Or if you have the original Qjet from the car send it to him for a full rebuild and resto. Here's a pic of mine from Ken.
Any idea the performance gain from them? I'd like to make a set for 350's and was wondering the differences between stock manifolds, ported manifolds, shorty headers, & long tube headers.
Surprised it's that much. I see they claim 35-40 for long tube so not much difference. It'd be interesting to dyno all 4 options that I mentioned back to back. I assume would require some minor tuning changes to optimize each.
On a 350 hp buick 350 run with long tube headers I would expect a 20 hp loss going back to manifolds. Shortys might only loose 15 hp. I can’t see the shortys being worth more than a 10 hp gain over manifolds. I do think that a well designed mid length header with a tri Y design could help the low and mid torque output over manifolds but still not as much as long tube headers. On a 450 Hp buick 350 with long tube headers I could see a 40-50 hp loss with manifolds or 20-30 hp loss with shortys. On a 300 hp low compression 350 with long tube headers I could see a 10 hp loss with manifolds or shortys. The higher the HP the more the long tubes help. I will say that my 6.0 LS (in a truck) gained a lot of low rpm torque with long tube headers and free flowing duals. It gained power across the board but it was the low end grunt that I appreciate. Towing trailers it makes a big difference.
From my experience with other engine types: - shorties produce extra peak numbers at the top of the power band where the manifolds really choke things out and minimal torque increase depending on how restrictive the stock manifolds are. - long tubes produce that extra power through the whole rpm range due to the scavenging effect.
Cheers for the reply & pics ur motor looks tidy - I don’t have the original carby, or much spare $$ as I’m painting soon - will order a set of shortys and change the carby in time - Thanks for the reply
