My 350 build...Advice needed!

[nextboat1]

Hey guys,
Thanks for all the great info! I spoke with my local machine shop about my plans for my engine and got a few prices. I also looked into a couple "crate" engines. Can anybody tell me the difference between these two engines other than price? Would the truck engine work with all my marine components bolted on?
http://www.michiganmotorz.com/350ci-vortec-base-marine-engine-1996current-replacement-p-109.html

http://m.summitracing.com/parts/nal-12530283

Not only is the summit engine cheaper, but they also offer free shipping.

 

[alldodge]

Michigan is a brand new marine engine
No core required

Summit is not marine engine and is a reman (rebuild)
Core is required

 

[Fishermark]

If you are thinking of going the crate engine route, then shop around. The Summit engine posted is a four bolt main. You can get the same basic engine in a 2 bolt main (part #12530282) for a couple hundred dollars less. (I am talking two bolt main caps - not main seal). You don't really need a four bolt main. Shop around and you can find them for around $1,850 with free shipping.

The Michigan motor engine includes the circulating pump and a "marine oil pan" - not sure what that means.

But bottom line - a crate engine makes good sense.

 

[nextboat1]

I'm really leaning towards the l31 vortec. Its built for a truck so I realize that there will be some things to change, but I'm curious if the cam will suit my needs. The listing for the engine says: paired up with a roller cam that has 0.414 in. of intake lift and 0.428 in. for the exhausts. Duration at 0.050 in. of lift is 191 degrees for the intakes and 196 for the exhausts, with 111 degrees of lobe separation." Will this cam be a good fit in a marine engine? I've read through similar posts, but haven't quite found an answer.

 

[Bondo]

but I'm curious if the cam will suit my needs.

Ayuh,.... It'll work just fine,...

 

[nextboat1]

I ordered the l31 long block! As much as I wanted to build my own, there was no way I could get what I wanted out of an engine for the price I paid for the l31. I plan to swap freeze plugs and head gaskets. My current manifolds and risers are orginal, so I plan to replace them. Any reccomendations? Should I stick with cast iron or would aluminum be worth the extra $?

 

[alldodge]

Cast iron heads will outlast aluminum heads but aluminum heads are great for reduced weight and so long as you have closed cooling or at least fresh water.

 

[nextboat1]

Thanks for the reply Alldodge. I'm gonna stick with the cast iron vortec heads. I'm looking more for recomendations on exhaust manifolds and risers. Forgot to mention that I boat solely on Lake Michigan and the boat is raw water cooled.

 

[alldodge]

Thanks for the reply Alldodge. I'm gonna stick with the cast iron vortec heads. I'm looking more for recomendations on exhaust manifolds and risers. Forgot to mention that I boat solely on Lake Michigan and the boat is raw water cooled.

Exhaust: Cast iron will be cheapest and will last a long time. Could get a few more HP from aluminum but at twice the cost, more for stainless. I don't see a 350 have a lot of problems breathing with cast manifolds

 

[nextboat1]

Should I buy aftermarket or would oem be worth the extra cost?

 

[alldodge]

Should I buy aftermarket or would oem be worth the extra cost?

After market would be fine, but note GML are know to have flatness issues but once fixed (if they are there) will have no more issues.

 

[nextboat1]

I shopped around a bit and think I'm going to go with the sierra manifolds and risers, paired with the oem gaskets. The website says that they are made in the USA and come from the factory painted.

My next question pertains to the head gaskets. I found a kit from felpro (part #17232) that has the gaskets I need, but I can't find the composition of the head gasket anywhere. Does anyone know if the head gasket included in this kit is stainless?

 

[alldodge]

I shopped around a bit and think I'm going to go with the sierra manifolds and risers, paired with the oem gaskets. The website says that they are made in the USA and come from the factory painted.

My next question pertains to the head gaskets. I found a kit from felpro (part #17232) that has the gaskets I need, but I can't find the composition of the head gasket anywhere. Does anyone know if the head gasket included in this kit is stainless?

That set is a marine rated set.
http://www.summitracing.com/parts/fel-17232

 

[nextboat1]

My engine came today and it looks great! I can't put it in until the spring, but I look forward to swapping everything over in the meantime. After reading through the documentation provided with the engine, I noticed that it calls for the use of a melonized distributor gear. Does the Thunderbolt 5 have a melonized gear or will I need to try to find one?

 

[DeepBlue2010]

Yes, it does.