455 using 307 exhaust?

[bigdan]

the W/Z 455 manifolds are far from being like 350`s .....

they have much bigger chamber and are almost similar to shorties .....
I have on hand a set of W/Z manifolds and a set of W31 manifolds no way do they compare .....

if you dont want to go the headers trouble , go for those W/Z manifolds ,you`ll be plenty satisfied!

 

[dogsht]

WZs, 3" pipe, an H, and some straight thru type muffs such as Magnaflows or Walker Ultra flows. Magnaflow 12259 Stainless un polished universal muffs would be ideal and fit under your Cutlass. I used the warehouse locator off Magnaflows site ordered mine from them for cheap and had them shipped to my door from the factory. Still not as cheap as a generic "turbo flow" but they are welded and better steel so they last and flow better ie you get what you pay for at the best possible price. No guesses on quarter mile times without more info especially gears. Without decent rear end gear you will leave a LOT on the table. You still will want at least as you can afford it a good cam a good performance valve job and first and foremost some good gears. 3.08s or 3.23s would probably be ideal with the 3 speed trans and that engine.