I have a 502 MAG MPI w/ a procharger m3sc setup thats being rebuilt. Its currently setup with the stock cam and stock mercury cast iron exhaust manifolds and risers, with the silent choice option. I would like to keep the exhaust as is for the moment due to budget concers, but am open to options.

I am wondering how big of a cam I can go with without water reversion? Would a 500EFI or 525EFI cam work? If not, would aftermarket manifolds with the shorter silent choice risers work with these? Or is my only option manifolds with the longer risers (ex: emi-511, 16" riser) and deleting silent choice?

Thanks for help and input

Headers on that app can run real close to the throttle body inlet tube ,especially with the 504 cooler you prob have with the m3. bullet , i believe it was , had a really lopey special grind that helped wake up the mag while also working well with the mag manifold plenum combo. Bang for the buck prob going to be cast alum gils and then have a cam ground for that set up later with roller conversion if needed. Upgrade the ignition , take it back up to 7 or 8 psi with appropriate pulley should be a strong runner

If you have good stainless late style risers now and let em go your exhaust upgrade will be under a thou.