I've been perusing the catalogs of some of the Olds parts suppliers since I bought my '72 442 earlier this year. I'd like to keep it stock appearing, with mild exhaust sound, but improve the performance a bit where possible. Although I have put headers on every muscle car and truck I've owned I want exhaust manifolds on this one. Quiet and smooth.
Looking at the OPG the other day I see that they sell "High Performance" exhaust manifolds that they say are based on the W30/455 exhaust manifolds. This sounds pretty good to me...stock appearing (except to the experts) but with increased flow, and they are brand new.
Has anyone tried these? The description says "2-1/4" outlet on the driver's side", is the outlet a different size on the passenger size? Do these create an issue with standard stock-style or aftermarket exhaust systems?
Any input is appreciated!
Thanks,
Jeff

 

I have a set from thortons in pa and I like them if your trying to keep a stock look.

 

I also have a set of Thorntons on my 72 442 350, I like them.

 

New (after a 20+ year hiatus) to Olds parts, is Thornton's an Olds parts house?

EDIT: Never mind, answered my own question with a quick Google search. I'll have to take a look at their offerings, thanks for the tip!

Jeff

 

Thornton builds a bunch of Olds parts. I also use there manifolds on my SB, it's a nice product and fits well also lets you use larger head pipes.

 

These are the same manifolds being sold by Thorntons and Ram Air Reproductions. I've posted many times about these. The "based on the W/Z manifolds" statement is tenuous at best. The only thing like the W/Z manifolds is the ribbing on the outside, which does NOTHING for flow. The SBO manifolds do not have enough room for the individual runners that the W/Z parts have.

Your call as to whether they are worth $300 or whatever the going rate is.

 

I'm not positive, but most all of the stock cast manifolds (single exhaust) have the drivers side outlet at 2" and the passenger side outlet at 2 1/4". These repros have them both at 2 1/4". That's why it is mentioned in their description.