Questions about 1975 450SL bogging and de-smogging

[Bondavi]

Engine runs great otherwise...Starts right up and goes fine from a standstill. However, anytime it hits 3500rpm, the car suddenly bogs and it will not go past this rpm mark. I either have to let off the gas or upshift. It has good power up to this point.

Any idea if this is timing related, or something's wrong with an electronic component? Thanks for any help!

As most know, 1975 was deemed the "worst" year for the 450SL due to the cats being on the manifolds. I'd like to make this car run better.

California does not have a smog law in effect for this model year. What I'd like to ask is what can I do to change the manifolds, and what smog parts can come off without impacting the engine's state of tune? I was thinking maybe putting in '73-'74 manifolds, with the air pump off? Anything else I could safely take off/out?

Thanks!



David