I am about to have my 1988 454 mags rebuilt by a local machine shop. They quoted me 2750 each which includes new pistons, valves, rings, bearings, timing chain, etc. Also includes dressing and running the engines and setting the ttiming and carb.

My question is, I would like about 40 or 50 more hp. I already have stainless marine manifolds. What cam,carb,intake, rockers will be good choices? Should I keep the quadrajets or go to holley's? I also have silent choice. Thanks for any info.

Don't know what type of exhaust you have, but more then likely you will have to change it if you beef it up.

If you already have Stainless eshaust. What was recomended to me was a Crane 241 cam and Gold roller rockers. The 241 is just slightly bigger than what Merc put in the 420. The Mag intake is a pretty good one. I was alos told I could stay with my 750 Quadrajet. I found a great deal on a set of 800 Holleys used, so I switched to those . Even with out the carb change should get you those 50 horses.

Im thinking a stock rebuild with the crane 241 cam, Crane gold roller rockers, freshening the quadrajets and calling it a day. What kind of HP do you think Ill be making with the above combo and stainless marine manifolds?

I would guess it to put you into that 420 area.