Just like Formula delivered it...I watched it go thru the old Miami plant and took delivery at the plant dock. I remember the Engine/Drive foreman remarked that the SS drives were shorter than the standard Alphas. Those motors made power all the way up to 6000 RPM. I ran that boat about 6~8 hours before I ran it over 50...after that I RAN it. I had a '88 'vette that had the same engine in it that was the same way...it just screamed. The only Pre Vortec Small Blocks I had any thing to do with that were stronger were 1970 LT-1's 350 Cu In/370 horse solid lifter motors that were wound to 7000 on several occasions. I drove Diego's sweet '89 272 SR-1 a few weeks ago with "massaged" 330 Horse 454's and it brought back memories of my '86. His 454's felt like a solid match on the "dig" for those 320's but his boat is done at 65...the EFI 320's just kept pulling all the way to 75.

Remember...1986...there weren't many Factory Boats that would run 75 MPH. I had a boating friend that had a '86 302 SR-1 with the cut down windshield and bolsters that couldn't get close to my 272 until the seas got to 3~5. I HAD to slow down to about 50 to survive and he could run past me at 65 no problem in the rough stuff with twin 400 horse 454's on TRS Drives. Honestly...those EFI 320's sounded like a Skill Saw cutting through 1/2" plywood at 5500 RPM. Those were the first marine engines I had where you could leave them for two weeks, walk out ,bump the starters and they would fire right up.

Twin 320 EFI's with Alpha SS drives were legendary performers. I'm like a kid at Christmas waiting to see how my old '79 255 Formula Liberator is going to compare with twin 400+ Horse Vortec Roller cam Motors on Bravo I's:evilb:

Awesome! Ss's, why don't we have them again?!

Mercury likes to exercise control. I have heard the guys at the upper end of this game discuss new projects from time to time and one recurring theme is to see how much you can accomplish without going to ANYTHING Merc.

Engine is renovated by the previous owner in 2008, and the drive gear ratio, I have no idea what is. can i find it somewhere on the drive? ordinary steel propeller that previous owner put on.
only problem is the rev problem and the speed im getting is 49 Mph(gps)

Poor mans way would be to mark the propshaft then turn the engine over with a socket 1 turn. Thepropshaft should turn approx. 1.5 turns or in sprinks boat it would be 1.3 then you will have an idea where its propped. Randy

do a compression test 1st...then go from there...

Determine drive ratio, if it is 1.32, then you need a 19" prop. 49 mph is not far off from typical 350/260, but that engine isn't making peak power at that rpm, a compression check wouldn't hurt either.

EDIT: and throw that aluminum prop in the garbage.