hi all----just recently picked up a very super clean original owner 17' Checkmate Diplomat bowrider. Really nice boat----has the original MCM 470 3.7L with an Alpha 1 outdrive----runs great but also wondering what my future options are if i want to swap out for bigger and badder. I have access to a still-in-the-crate 1987 GM Targetmaster 350 engine that i believe was slated to be installed into a ski boat and never was----dont ask!!!----or possibly a nice fully dressed 4.3L that i could drop in--someone in the local want ads was selling one from a 1988 boat that was up for maybe 1300 bucks or so??--anyone have any info concerning the fit and limitations on power/hull withstanding if i want to do a swap??? im sure for at least this year and possibly next the original 4cyl will be in there but any input on my options would be appreciated----thanks

I would build a healthy small block. 350, 383. Keep the stock engine when it is time to resell. Small blocks are pretty cheap to build.

yeah ive got that brand new motor to build up some or my buddy wants me to take the engine from my 4speed 78 nova and put it in there----that i built 2 years ago and it is still real fresh -----nice cam not real lumpy still idles ok----30 over on the bore----10 to 1 compression and an edelbrock dual plane manifold rpm air gap----ive heard you ned to run a single plane on boats though. is that true?? also heard too much valve timing overlap with a lumpy idle cam is no good either...feedback?? but as far as the hull and size of the boat 17' i should have no problem with the swap?? thanks for the reply

Do not put a car motor in the boat. It will not last, boat motors goes through way more stress than a car motor.

yeah thats why the 350 in the nova is staying in the nova----but i need to run some numbers and do a little research on the 1987 350 targetmaster still in the crate that i have----according to my father it was installed in a boat application but taken out even before any hours were accrued----???---maybe just someone opted for the upsize right away?? anyhow if i get all the block numbers and stuff how could i run them to find out origin and if this is truly a marine engine?? thanks for the info...