It's funny because I wasn't really sure how much extra performance I was going to get since I never got a chance to dyno the motor (lack of $$$). My initial reaction was that of mild disappointment but I've come to realize it was a pretty descent increase in performance.

I'm running a single application (21' production bowrider) and not a twin so it is difficult to make a similar comparison to your setup. Original motor was a 1995 350 Mag EFI/MP rated at 265 hp at the prop. New motor is a standard bore (brand new block) stroker yielding 377 cid. Kept same fuel injection system but installed bigger injectors, new heads, cam and tuned the EFI myself. Looks IDENTICAL to the stock motor but is far from stock. Runs like a charm and lights off immediately. PM me if you want more details.

A supercharger and Imco exhaust will net 500hp, if you make it into a 383 stroker, with small cam change, it would net 600hp.

Dustin,

How much static compression can you utilize on a Whippled SBC?


Sorry for the hijack....

does the 350 mag have cast,or forged pistons?

dustin,i agree but if he went with a hp500,and wanted to upgrade ,by adding one of your kits he would be in the 750 hp range,if he sold his 350 mag,he would not have to spend a ton of money difference for a hp500,and it has much more potential for upgrades down the road.then he would have some leftover money to upgrade the drive after it ****s the bed.

And how much would that cost?

I can't speak for all Merc 350 Mags, but my 1995 EFI/MP motor had a cast crank, and hypereutectic pistons but a roller cam (GM"395" cam 196/206 duration @ .050" ,.394” / .403” 109 LSA). Stock compression was 9.35:1.

My initial impression was that all Mag motors had forged internals except the pistons. Some may have, mine did not and I believe that is the case for most Mag motors.

if you wanna stay with a light weight motor, to keep your hull balanced, check out my roller 383 stroker in the swap shop. it's 450hp, built right, tons of torque, and also available is a real nice Gil Offshore aluminum exhaust system with long tails. real good price and fresh, runs perfect all around. I'm starting a new project with a blower motor and starting fresh, to be honest, I'm surprised I still have it! It's alot of power cheap... not sure if pointing out for-sale items is frowned upon in this section, just thought it was a good fit for what you're trying to do.

With the exception of the Mercury Remanufactured 383 cu in that is no longer for sale (9.6:1 with Forged Pistons) all the 350s and 377" did not have forged pistons. I could not find any specs on the cranks as to whether they were cast or forged. Cam specs for the 6.2 is: .452/.465 lift, 214/220 @.050 duration (Same as CRANE 2032)
Rpm range 2000-5500

There is your easiest solution. Keep your original engine when you go to sell the boat or use it to finance the new motor. With that size hull You should see about 8-10 mph per 100 hp