My old 260 hp 350 cid was tired (1985) so I looked to replace it in 2007. The marine mechanics want you to go to Merc. and pay huge money. GM parts depts. will sell you a crate motor for a very reasonable price. There will be NO warranty if it is used in a marine invironment. I went to a speed shop in Kamloops (Garrett Engines) and got a complete Long Block built into a 383 "stroker" balanced up, big heads, etc. and plunked my marine intake, carb., FWC manifolds, etc. That cost $4,000. Note: I did have problems at first as I didn't have roller tipped rockers or very HD push rods so I pushed 3 push-rods up through the stock rockers. All fixed now and I am very pleased. The one problem that does remain is that although I have a 2006 Merc. leg on the boat it is an Alpha 1. You have to be gentle with the throttle or I think I'll twist it clean off. I should have changed out the leg to a Bravo series to handle the torque.
Oh yeah.....As my boat lives far away from me I hired the local marine mechanic to re+re the engine. A quoted 10-12 hrs. turned into 3 full days. There is a lot of work involved swapping parts to turn a long block into a running marine engine. Automotive to Marine has some quirks that must be rectified.
