3.7 swop out to a 4.

[philbullet]

I may be looking to swop out the 470 to a 4.3 this winter.
What thing's i will need to convert ? I can get a 4.3 short black or long block with no problem and my brother is a auto mechanic.
1. Y exhaust pipe. What type or kind?
2. what exhaust mantifold and riser's are require?
3.forward motor mounts? I know i will have to make or fiberglass new mounts in bilge.I can do fiberglass work my self.
4. anti freeze cooling system? will any thing from the 470 would work? i have a 4" heat exchanger
5. wiring? that should be a problem iam hopping brother and i can figure this out.
Any other input would be appreciated.
I also no where there is a boat with twin 4.3 but it was sunk and oil in block dosn't look to good,they may be locked up and they also have the batwing exhaust mantifolds which ive heard bad things about on this fourm.Motor look in reel good shape on outside and didn't have many hours on them,but ran with raw water cooling system,no heat exchanger's.
May not be worth touching and i haven't ask the guy if he is gona sell them or just want to get it out of his yard.
Thanks

 

[ziggy]

while i aint done it. i got an L6 i'd like to convert to a 4.3. what i would consider is a doner boat. a spent boat w/ a 4.3. prefeabley not sunk. i want it all. from gauges to prop. i don't think anything from my L6 or your 470 would be compatible. ya need the package. me too.
and yep, we'd both have to do glass work for motor mounts.

 

[achris]

As long as the original is 'R' drive or later, the engine will drop straight onto the inner transom plate mounts. If it's earlier than that (1983), forget it, you need pulley to prop.

If you're changing from 470 to 4.3, you're also going to need a 4.3 flywheel housing and coupler.

Chris.....

 

[philbullet]

yep i wish i can locate a donor or a cheap running boat with a 4.3 and it would be a lot easier

 

[Bondo]

yep i wish i can locate a donor or a cheap running boat with a 4.3 and it would be a lot easier

Ayuh,..... Piece mealin' a full dress Marine motor, outgha a long block is Expense,...

When I did 'bout what yer about to do, I bought a frozen, fully dressed motor, for $500.00, 'n figured I stole it,....
It was fairly recent production Merc, T-bolt ignition, Carb, etc,....

 

[philbullet]

Well iam looking at other option's also,it seems to be hard to find a decent 4.3 in a boat running at a good price.LOL
Ive been looking and found some complete eng. to boat's with problems.
I found a complete boat with a 305 hp v8,motor looks reel clean and has no title to boat but that doesn't concern me 3000.00 ,as all i want is the motor package.I
just dont know if i can make it fit but iam sure it will,I have the width and the 470 4 cyl. should be the same?
I should find something for a winter project.

 

[stonyloam]

Hey Philbullit, for some reason could not respond to your 305 thread, but here is some info: If you are talking about a 305 Chevy V8 (5.0. L). About 400 pounds, about 170 vs 230 HP.

 

[Fishermark]

while i aint done it. i got an L6 i'd like to convert to a 4.3.

Ziggy - say it isn't so!!! You're one of the long time fans of the inline six!!

 

[achris]

while i aint done it. i got an L6 i'd like to convert to a 4.3.

Ziggy - say it isn't so!!!

You're one of the long time fans of the inline six!!

Even a die-hard will eventually see the light, and realise the V6 is stronger, faster, more fuel efficient and more reliable.
The only problem for that conversion is the transom plates. The in-line 6 and the V6 are from the wrong sides of the 1982 demarcation line. You can still use the drive, the ratio is the same, as long as you change the yoke, but the flywheel housing on the in-line 6 has a 14" rear mount spacing and the 4.3 has 10" spacing.

Chris.......

 

[philbullet]

Philbullit, for some reason could not respond to your 305 thread, but here is some info: If you are talking about a 305 Chevy V8 (5.0. L). About 400 pounds, about 170 vs 230 HP.

Ok thanks,yes ive just join this sight and have some trouble editing and posting pics for some reason.Still trying to learn this board.