Second attempt(thread didn't post 1st time)

[starsnstripers]

I have reworked my transom in my 1972 SS215 Slickcraft 21.5' to take a Mercruiser instead of the OMC stringer it once had. I Have the transom assy. plate,gimble, and 1.50:1 drive from a V8. I was going to put a 305 or a 350 in it, BUT! I found a boat today i can buy reasonable with a good 4.3 eng. and Cobra drive. (1) Can i use the OMC manifolds to hook up to my Merc exhaust Y tube? or do i need Mec manifolds?(2) The 4.3 is a Gm It is a 1.50:1 eng correct? (3) Since i already did my transom over I probably wouldn't use the whole Cobra set up, Opinions?

 

[starsnstripers]

Re: Second attempt(thread didn't post 1st time)

Also Will the V8 Merc exhaust tube be ok to use with the 4.3? thanks

 

[Bondo]

Re: Second attempt(thread didn't post 1st time)

Nope,... You can't put an OMC dressed motor, on a Merc. transom assembley...
The OMC exhaust is a different diameter,....
And, That's just the 1st Problem you'll run into...

4.3s use a 1.84:1 or 1.65:1 ratios,... 1.5:1 is for V8s...

 

[starsnstripers]

Re: Second attempt(thread didn't post 1st time)

thanks Bondo, so i can use the motor, i'd just need manifolds and outdrive. will the 4.3 with Merc. manifolds work on my V8 exhaust Y tube?

 

[starsnstripers]

Re: Second attempt(thread didn't post 1st time)

Well what about putting the whole drive setup in my boat, 4.3 W/ OMC Cobra Drive? I'd have to redo the transom, But saves me from getting a drive and manifolds. What would you do? thanks

 

[starsnstripers]

Re: Second attempt(thread didn't post 1st time)

Whats the Horse Power on an 86 4.3? 170ish?

 

[haulnazz15]

Re: Second attempt(thread didn't post 1st time)

Just go find a 5.7L V8 to go with the equipment you already have. You wouldn't be happy with a 21' boat and a v6 anyhow. I wouldn't put a single OMC item on my boat if I were you. The outdrive and transom/exhaust stuff is more expensive than finding a used 350 marine motor.

 

[Bondo]

Re: Second attempt(thread didn't post 1st time)

will the 4.3 with Merc. manifolds work on my V8 exhaust Y tube?

Ayuh,..

Whats the Horse Power on an 86 4.3? 170ish?

Ayuh,.. with a 2bbl... about 200+ with a 4bbl...

Well what about putting the whole drive setup in my boat, 4.3 W/ OMC Cobra Drive? I'd have to redo the transom,

Ayuh,... I think I'd rather Shoot myself 1st.... But whatever Trips your trigger...
The Transom hole is the Same as the Merc...

Just go find a 5.7L V8 to go with the equipment you already have.

Ayuh,.... Amen....
SBCs are a dime a Dozen,....
A Hundred dollar junkyard pickup truck motor with brass coreplugs will put you on the water,+ give you somethin' to Work with....
Brand New GM Goodwrench motors are still only $1500. or Less...
Nevermind,... I see you don't have the motor's Dressings....
Are you finding your parts along the coast, or inland,..??
You need to find a frozen split SBC Dressed as a Merc,+ a $100. 350 motor with brass coreplugs...
Then you'll only need Manifolds...

 

[starsnstripers]

Re: Second attempt(thread didn't post 1st time)

I think i'll get the 4.3 and get manifolds and a 1.84:1 drive. I think that motor will be more efficient and plenty of oomph! I had a 160 hp L-6 in my last years boat same thing SS-215 Slickcraft and it went just fine. An extra 15hp and better fuel effiency than a straight 6 and a V8, i'll be a happy boater.