Need To Replace '93 4.3 and Wondering About Going To Vortec Head Motor.Best Year?

[jcbache]

Got a '93 Fisher 19 SV I/O with the 4.3. PO didn't winterize, cracked it, overheated it, according to him it's shot. He pulled it out and stuck it in a shed. I'm not going to try to figure out "how shot" it is. He's an auto mechanic and he said heads are cracked. So, of course I would like more power and efficiency of a Vortec- headed motor, and will probably up the ante with a 4 barrel carb. Anyway, my question is what year re-man Vortec motor would be my best option in terms of re-using some of the old '93 motor parts and ease of bolting up to the Alpha. If anyone has done this ( I'm sure tons of guys have!) and would care to help with some of the specifics about bolting up all the stuff that won't come with a re-man long-block ( probably going to buy one from Rapido Marine) I would greatly appreciate it. The boat is welded aluminum ( deck and all!) so the balance-shaft motor might be a good idea in terms of vibration. I'm thinking that a 96-99 motor ( balance shaft, good Vortec 8-bolt intake heads) would be the one. What will I have to change in terms of flywheel and Mercruiser parts to bolt up to the existing '93 Alpha? Stuff like that. Thanks for any input!!

 

[Bondo]

Re: Need To Replace '93 4.3 and Wondering About Going To Vortec Head Motor.Best Year?

Got a '93 Fisher 19 SV I/O with the 4.3. PO didn't winterize, cracked it, overheated it, according to him it's shot. He pulled it out and stuck it in a shed. I'm not going to try to figure out "how shot" it is. He's an auto mechanic and he said heads are cracked. So, of course I would like more power and efficiency of a Vortec- headed motor, and will probably up the ante with a 4 barrel carb. Anyway, my question is what year re-man Vortec motor would be my best option in terms of re-using some of the old '93 motor parts and ease of bolting up to the Alpha. If anyone has done this ( I'm sure tons of guys have!) and would care to help with some of the specifics about bolting up all the stuff that won't come with a re-man long-block ( probably going to buy one from Rapido Marine) I would greatly appreciate it. The boat is welded aluminum ( deck and all!) so the balance-shaft motor might be a good idea in terms of vibration. I'm thinking that a 96-99 motor ( balance shaft, good Vortec 8-bolt intake heads) would be the one. What will I have to change in terms of flywheel and Mercruiser parts to bolt up to the existing '93 Alpha? Stuff like that. Thanks for any input!! View attachment 216608

Ayuh,.... The '93 has the electric fuel pump, correct,..??

I believe a block from '93 to '00, possibly newer will work just fine, with Vortec heads added,....

Though there's a thread bouncin' 'round here somewhere that says the blocks newer than '10 are some what different,...

Btw,... Vortec heads, 'n intake can be added to any vintage block,...

 

[jcbache]

Re: Need To Replace '93 4.3 and Wondering About Going To Vortec Head Motor.Best Year?

Thanks Bondo. What do you think about the balance shaft motors? I know it's not absolutely necessary, but if GM went through the trouble to tool up and build 'em with balance shafts there must be something to it. I guess there was a little more engineering needed to make a 4.3 run smooth than just basically lopping two cylinders off a 350 motor. A Fluid Damper would probably do the same job as a balance shaft but... might as well take advantage of GM's research work and get a balance shaft motor. I'm thinking that a tin boat ( with no wood deck, just welded aluminum) could benefit from the extra "smoothness". Doesn't seem like a bad idea. I guess the timing cover is different, but do you know of anything else? I'll have to run an electric fuel pump but that's no biggy.

 

[Bondo]

Re: Need To Replace '93 4.3 and Wondering About Going To Vortec Head Motor.Best Year?

Thanks Bondo. What do you think about the balance shaft motors? I know it's not absolutely necessary, but if GM went through the trouble to tool up and build 'em with balance shafts there must be something to it. I guess there was a little more engineering needed to make a 4.3 run smooth than just basically lopping two cylinders off a 350 motor. A Fluid Damper would probably do the same job as a balance shaft but... might as well take advantage of GM's research work and get a balance shaft motor. I'm thinking that a tin boat ( with no wood deck, just welded aluminum) could benefit from the extra "smoothness". Doesn't seem like a bad idea. I guess the timing cover is different, but do you know of anything else? I'll have to run an electric fuel pump but that's no biggy.View attachment 216626

Ayuh,.... You must have 1 of the last motors, before the balance shaft,...

Mine is 'bout that age, but has the balance shaft,...'n the electric fuel pump,...

 

[jcbache]

Re: Need To Replace '93 4.3 and Wondering About Going To Vortec Head Motor.Best Year?

Thanks