GM 350 Special Performance Crate Engine 12355345

I just bought a vehicle with the GM 350 Special Performance Crate Engine (12355345) in it. Didn't get any documentation.

Was wondering if anyone could tell me the specs for what fluids this engine requires. (What minimum octane fuel, synthetic or regular motor oil, which power steering fluid.)

Thanks!

Reply to
Joshua Nelson
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Hi Joshua! I just looked your engine up in my GM Performance Parts Catalog and what you have is a 330 H.P. 350 H.O. engine. The engine has 380 Ft.Lbs. torque @ 3800 R.P.M. and has a 4 bolt main. It has the 64 cc Vortec cast iron heads, a nodular iron crankshaft, PM steel connecting rods and cast aluminum pistons. The heads have 1.94" intake and 1.50" exhaust valves.

Maximum Recommended R.P.M. 5500

Compression Ratio: 9.1:1

650 cfm carburetor recommended

Given the reasonable compression ratio, "Regular" pump gas of 87 octane or higher should suffice, but if you notice and run-on (dieseling) or pinging, go a bit higher. Definitely no more than 91 octane would be required.

The engine comes from the factory with regular motor oil 10W30SG oil and PF1218 ACDelco oil filter (PN 251605610). Synthetic oil is a matter of personal choice, but I'd recommend it if the engine is already broken in. From personal experience, I have a ZZ4 crate engine in one of my cars (355 H.P., 405 Ft.Lbs. torque) and I noticed an appreciable difference in performance when I went to Mobil 1 synthetic after the break-in period. Some people swear that their mileage improves with synthetic oil as well and this makes sense because synthetic oil reduces friction in the engine.

The motor doesn't come with a power steering pump, so your pump is possibly the stock one for the car. I'd suggest that you contact the person you bought the car from and find out what the pump is out of and take it from there.

Here's a link that lists the parts in your engine:

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Let me know if I can be of any further help.

Reply to
Sting Ray

Wow, that is a ton of info. Thanks for all the help!!!!

Reply to
Joshua Nelson

Wow, that is a ton of info. Thanks for all the help!!!!

Reply to
Joshua Nelson

My pleasure Joshua. So now you have to tell us what car the engine is in???

Reply to
Sting Ray

It's in a 1981 Jeep CJ. The next thing most people say is "Wow, I bet that thing must really move!" But due to the extremely low gearing and large off road tires I can't do much over 50mph on the highway, so you won't see me at the local drag strip. But I can climb a near vertical rocky slope with it!! It's set up with a Holley ProJection

4di fuel injection system so I can get fuel to the engine when the jeep is at odd off-road angles. I bought it already built this way and have limited mechanical skill so I am trying to get up to speed.
Reply to
Joshua Nelson

That sounds like one cool project! F.I. is the way to go with that beast. Carbs don't always work so well at odd angles to the turf! *lol* Good luck with your CJ!

Reply to
Sting Ray

But sometimes they do. I flipped my go-kart once and it was still running. :-)

GW

St> Carbs don't always work so well at odd angles to the turf! *lol* Good luck

Reply to
Geoff Welsh

LMAO! :-)

Reply to
Sting Ray

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Out of curiousity, is it necessary to do oil pump modifications to assure that it can pick up a supply when you are at some of those odd off-road angles?

Ray

Reply to
Raymond Makul

Honestly I have never thought of that and no such mods have been made. Usually it is just at a > 40 degree angle for a few seconds while crawling up a steep embankment. Long enough that a carbureted engine could stall, but not long enough to worry about the oil running out of the engine.

Reply to
Joshua Nelson

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