i have a 454 420 hp in donzi 22ft runs in upper 60s would like to see mid to high 70s
what would be the best and most relible blower setup to bolt on dont want to betaking it in to fixed all the time im not very good at wrenching
drive is a trs

Buy a lightly hp500efi or a 525sc..... Otherwise you will be wrenching more than you want

What he said. If you are not into wrenching, forget it. It's a long and bumpy road with many headaches and possible long periods of down time. Don't forget to upgrade your steering, fuel system, cooling system and drive line. If that is not possible, don't increase the power. Big power and upper 70's demands good fuel supply and cooling, full hydraulic steering and a drive that can handle the power, if you don't already have it. You'll need about 525-550 hp to achive your goal if 420 hp puts you in the high 60's.

i thought a 525sc was a 454block with a blower

that is correct,7.5 compression,small hydraulic cam,factory gm rectangle ports,and a weiand 177 blower,it runs 35 degreese total ignition timing and comes with i 4 barrel carb.and other than normal maintenance,it will run forever,very dependable.

if your engine is a real merc 420,it has 8.8 to 1 compression ratio,a little high for a blower,but it will work if you keep the boost under 5 lbs.it has forged pistons,7/16 rod bolts,and a gm forged crank,put a small blower on,and have a good fun time.

what would be a fair price for a 177blower ? or would i be better off just have the motor rebuildt to get 500hp out of it motor is a 1979

500 is easy to achieve with the right parts,what is your budget for this project,and where are you located?

lake geneva

whats a fair price for a177 blower