rebuilding this winter

[trkr75]

So I am thinking about rebuilding my 5.0 this winter. I want a few more ponies out of it when I am done. Since I got the boat I have put a edelbrock 650CFM marine carb on, MSD distributor and 6al ignition box to it. What do you suggest for engine upgrades. The boat is a 85 four winns liberator 221 alpha 1

Thanks,
Ken

 

[John_S]

Re: rebuilding this winter

Replace with 350 long block w/vortec heads. Ignition components must be marine, like the carb. Check the model number on the Edelbrock. They make 600 and 750 cfm 4brl marine carbs.

 

[Bondo]

Re: rebuilding this winter

Replace with 350 long block w/vortec heads. Ignition components must be marine, like the carb. Check the model number on the Edelbrock. They make 600 and 750 cfm 4brl marine carbs.

Ayuh,... Agreed, drop in a 350...

 

[FreeBeeTony]

Re: rebuilding this winter

Ayuh,... Agreed, drop in a 350...

Or build a 383..............

The more I see guys rebuilding their SBC's the more I wish I built a 383............but my 350/Vortec is running great, really can't complain.

 

[trkr75]

Re: rebuilding this winter

will the Alpha 1 hold up to the power from a 383? Also will the exhaust and intake transfer from the 5.0 to the 350? I am on a somewhat small budget so I want to use what I can from this motor. I won't skimp on things I need to buy but would like to reuse what I can.

 

[greg82255]

Re: rebuilding this winter

The alpha drives are rated for 300 hp but several people run 383's with them. As long as you are careful it should be fine. The intake and exhaust will transfer without a problem, unless you use vortec heads.. then you need a new intake and an electric fuel pump. You can buy a 350 long block from Rapido for 1450, and they offer a vortec long block for 1850 that isn't advertised on the website. 383's can get expensive but lots of people say they are worth it (I'm actually going to build one this winter...)

 

[John_S]

Re: rebuilding this winter

Yes, you do need a different intake using vortec heads and center bolt valve covers. The electric fuel pump is only neccessary if you get a long block without a mechanical fuel pump mount or use a cam that doesn't have that lobe. You can build a pre-87 vintage block to work with vortec heads, withould going to a '96+ block and dealing the few changes from that. The pre-87 block would also reduce changing flywheel, starter, and coupler, but you keep the old two-piece rear main seals, etc.

Standard Head 350/4brl = 250HP @ Prop
Vortec Head 350/4brl = 280HP @ Prop
Conservative 383/4brl = 320HP @ Prop

Your current 305/4brl is probably around 200HP @ prop

Outside of the HP, you probably want the extra torque to reduce planning times on your boat. The more displacement, the better the low-end torque. Like others, I'd like to build a 383, but the alpha creates a quandry for me. I still want to launch rapidly for skiing and other water toys, but afraid it will wreck the drive. Having the extra torque, and controlling my right arm would be difficult. For now, staying with the 350 vortec.

 

[Volphin]

Re: rebuilding this winter

I'd build a 383. An A1 will hold it fine.

V

 

[69GTOby]

Re: rebuilding this winter

I would just buy a standard 350 long block and transfer all your stuff over with ease. I would consider putting in a Vortec 350 and dealing with the few necessary changes, no big deal, perhaps if you have the money for an intake and whatever else, go for it. I probably wouldn't go the 383 route. You probably won't have problems with the Alpha drive, but it's even more money, and why risk it? Plus going from 305 to 350 CIs will yield a considerable power increase for you, and a rock solid drivetrain. In the end, it's up to you and your wallet.

 

[trkr75]

Re: rebuilding this winter

The alpha drives are rated for 300 hp but several people run 383's with them. As long as you are careful it should be fine. The intake and exhaust will transfer without a problem, unless you use vortec heads.. then you need a new intake and an electric fuel pump. You can buy a 350 long block from Rapido for 1450, and they offer a vortec long block for 1850 that isn't advertised on the website. 383's can get expensive but lots of people say they are worth it (I'm actually going to build one this winter...)

So I am thinking this 350 with the vortec heads sounds like what I need. I have a few questions / would like your opinion, what kind of intake would you go with, will it use the same motor mounts or will I have to get new mounts, and as far as wiring goes it should all be the same right? any other things I might be missing?
Thanks,
Ken

 

[StevNimrod]

Re: rebuilding this winter

For the intake - and if you didn't want to go stock - Edelbrock and Weiand both make good dual plane units.

Mounts will be the same.

The wiring will be the same; but if you need to run an electric fuel pump you'll have to add a safety circuit through an oil pressure switch.

The 383 is a good way to go if you're going to do a build; you aren't talking much money over a 350. If you do decide on a 350, the Vortec vintage blocks can be had with the hole already drilled but be careful - many of them have the hole started, but not drilled through.

 

[FreeBeeTony]

Re: rebuilding this winter

If you do decide on a 350, the Vortec vintage blocks can be had with the hole already drilled but be careful - many of them have the hole started, but not drilled through.

What hole are you talking about?

 

[StevNimrod]

Re: rebuilding this winter

For the mechanical fuel pump.

 

[FreeBeeTony]

Re: rebuilding this winter

For the pump itself?

 

[trkr75]

Re: rebuilding this winter

For the intake - and if you didn't want to go stock - Edelbrock and Weiand both make good dual plane units.


The wiring will be the same; but if you need to run an electric fuel pump you'll have to add a safety circuit through an oil pressure switch.

I plan on using a electric pump. What is the safety switch for? (other then safety) Not sure what you mean by through a oil pressure switch, sorry still a newbie here