I purchased the Carter Weber carbs from Tom Langdon and also the HEI. Running the stock 3:90 rear with 3 speed + Borg Warner overdrive in my 55 1st series. Runs great and very resposive. I couldn't be happier. I also have Fenton cast iron headers with very small glass packs. I like the exhaust sound until I go above 2500 RPM which isn't too often. I see that Cosmo uses an X pipe. I am thinking of installing one. Would that mellow me out a little in the 2500+ RPM?

Thanks
Grant