I'm thinking of changing from TBI to carb, and changing the cam from hydraulic roller to solid flat tappet. I believe I'm going to use a standard GM HEI distributor correct? Vacuum Advance? Are there HEI distributors that came without vacuum advance, and if so, can they be converted to vacuum advance? Any other advice? Thanks.

 

not sure what you're asking for, ecm controlled distributors don't have vacuum advance, non ecm controlled distributors do. you need a non ecm controlled hei distributor for your swap

 

Get an older style HEI w/ vaccuum advance or get an msd timing computer to control advance.