I am in the process of upgrading the existing exhaust system on my 66. I have a Crate 350 with Dynomax headers, Dynomax Turbo mufflers and a local shop 2.25 exhaust system. Two questions please.
(1) Will the Dynomax Ultra's be louder that my existing Dynomax Turbo's? I desire for the car to be louder. But not sure about Flowmaster loudness.
(2) I believe Dynomax Ultra's are 14" or so long and the Flowmaster's run around 19", so can I use the Flowmaster American Thunder System minus their mufflers and the Ultra's??? I am concerned about the length difference and where would I make the 6" or so up at? Has anyone been this route? Thanks for any suggestions, I appreciate any help.

Jesse Robertson

Yes, the Dynomax welded ultraflow will be louder than their turbo muffler. The Ultraflow is a straight through design where the turbo is a 3 pass design.

FYI, the welded UltraFlows are available in a 20" long case model which will be the closest in size to the Flowmasters your removing. I put a set of 3" in/out 20" long case on mine (17233 I believe). If you go to Dynomax's site, they have part numbers and dimensions/diagrams for all their mufflers.

let us know what you end up doing and how it turns out.

I have been thinking about the same thing, but may end up going with the turbos instead of the ultras if they are too loud.

I have the turbo's on my car now. They are pretty tame at idle, but as soon as you open it up there is no doubt your in it. :D I am looking at going with the welded ultraflo's.