78 Mercruiser 228 "gm 305" swap

[wildways1976]

I recently picked up a 78 22' Starcraft Cuddy... The engine I have found has water in 2 cylinders and is seized.... Im swapping out the 305 for a 93 350... My question would be " will the cam from the 305 work in the 350 ?" Id like to get as much hp out of the 350 without spending a couple of wads...

 

[Davetowz]

The cam will work in the 350 but the grind is probably not what you are looking for for the performance. Plus whatever wear is on the cam from being in the 305.

 

[flipbro]

I wouldn't run a used cam. There fairly cheap. Go with a 420 443 grind. That will give you alittle more torque. You're also going to need a different flywheel and coupler..

 

[Bondo]

Ayuh,.... What did the 350 come out of,..??

I'd probably run the cam that's in it,...

 

[wildways1976]

It came out of a 93 chev k1500 truck

 

[Bondo]

Ayuh,.... Then don't worry 'bout the cam,....

A truck cam is 'bout the same as a marine cam,......

What ya Don't want, is a fire breathin' Hot Rod cam,.....

 

[wildways1976]

The stock 305 Mercruiser is rated 228 hp, this stock chev 350 is 210 hp... Didnt really want to loose any HP but this is what I have to work with..... Boat is a 1978 Starcraft American 22 Express.

 

[Scott Danforth]

As Bondo pointed out, cam is fine. However you will need to change the core plugs to brass, and I would recommend replacing the head gaskets with marine friendly

 

[wildways1976]

Already in the works Scott, I appreciate the heads up on the core plugs.

 

[Bondo]

The stock 305 Mercruiser is rated 228 hp, this stock chev 350 is 210 hp... Didnt really want to loose any HP but this is what I have to work with.....

Ayuh,... The horsepower changes are changes in Induction,.....

2bbl. carbs, vs: 4bbl carbs,....

4bbl. 350s are 260hp,.....

 

[wildways1976]

Im using the intake from the 305 which is a 4bbl setup..... The 350 was a TBI, 64 cc heads, its only a 2 bolt but I am not building a speed boat.

 

[Bondo]

its only a 2 bolt but

Ayuh,.... Few boat motors are 4 bolt,.....

Ya really don't need a 4 bolt block, unless yer goin' for a horsepower per inch, or higher,.....

 

[Scott Danforth]

My 350 2-bolt vortec headed, camed up SBC was ridden hard and put away wet and was still running strong when I pulled it to go BBC. Nothing wrong with 2-bolt blocks

 

[flipbro]

The intake from the 305 will not bolt up to the 350. Those are swirl heads and require a intake with the center bolts at a 60 degree angle I believe..

 

[Bondo]

The intake from the 305 will not bolt up to the 350. Those are swirl heads and require a intake with the center bolts at a 60 degree angle I believe..

Ayuh,.... Good Catch,..... I hear there's a die-grinder, 'n beveled washer cure, but ain't tried it,....

 

[wildways1976]

I am not positive this engine is a vortec...

 

[Scott Danforth]

93 is not vortec unless someone put vortec heads on it. Vortecs came out in 96.

 

[flipbro]

Ayuh,.... Good Catch,..... I hear there's a die-grinder, 'n beveled washer cure, but ain't tried it,....

Yes that does work. I pulled that off last year and had no issues. I went out and bought a edlebrock 2401 to replace it for this season..

 

[wildways1976]

Next ?, the flywheel is gonna be different. I was told to use the flywheel from same year as motor standard trans flywheel.... Will my coupler work with the new flywheel?

 

[flipbro]

No! Your going from a 2 piece rear main to a 1 piece. The bolt pattern is .58 smaller on the 1 piece. Also look on the 93 block does it have the hole drilled for fuel pump?