I have found a local builder that has a 350 small block. He is in the process of moving his shop and is looking for the build sheet. I know this sounds funny but he is local and has a good rep with the racing folks in the area. Anyway here is what I know about the engine so far.
- 7 quart moroso oil pan (will this fit in my 75?)
- Dart 202 aluminum heads w/HD springs
- Comp cam Gross Valve Lift is 540 for both intake and exhaust, duration of 284 and lobe spacing of 106.
- Barry Grant 750 double pumper, demon line
- Air gap intake,not sure of model (will this combo fit under stock hood?)
- Mallory distributor (do not know model)
- engine comes with starter and flywheel as well.
I hope to get more info today on specifics. Here is the part the owner told me. The engine was spec'd at 435hp however he wanted to race with it so installed a thinner head gasket and figures it is now in the 475hp range. He stated I will have to detune to run pump gas. He wants $200 to detune. Estimate of 12:1 compression with the current thinner head gasket. I am asking about warranty. The top end has never had fuel through it. He is asking $5500. Thoughts?
scott


Here is what I learned today. I am planning to go with crate motor but thought I would throw the additional info out in case something in there should be changing my mind.
4 bolt GM Block
Bore 4.030
Exhaust valve 1.600, Lash .018
Intake valve 2.080, Lash .017
Pistons 4.030 TRW
Crank - GM Steel .010 mains .020 rods
Lifters – Flat tappet comps
Valve Springs – isky
Comp Belt Drive (Dry)
Crane Rockers
Comp Pushrods
Dart Aluminum Heads
Bearing clearances .02 rods, .0025 mains
Piston Clearance .006
Top Rings End Gap .018
Second Ring End Gap .014
Valve spring seat pressure 135 pounds, open pressure 160 pounds
Installed Heights 1.900
Piston in Hole 9.015, .015 deck, .010 in hole (not sure what all this means)
Camshaft 105 degree in centerline 1 degree advanced.

Scott

 

I think spending that much you should consider at least a 383
build. You can buy an all new GMPP 383 less the intake, carb,
dist. for $5300.00. NAL-12498772. www.summitracing.com.

 

How is he going to detune the engine so that you can run pump gas without a complete teardown and rebuild? Why not buy the engine you really want from GM?

 

The only things that stand out to me are the numbers jumping from 435 to 475 with just a gasket change? I'm skeptical. And there is no need to even try and run 12:1 on the street. If you have other plans for the car then you may want to consider 12:1. I think I would listen to little mouse on this one.

 

If you are going to spend that money, go for a crate motor. You won't have to ask for a warranty.

 

 

I added some information to original post that I learned today concerning this engine. Still leaning towards a crate motor unless somebody sees something in these numbers that says I should buy it. Thanks for looking.
scott

 

Walk away from that one. I also liked the part about the 40hp increase (over 10%) from the head gasket change.

 

There's literally no way to get enough compression out of a 12:1 motor to get down to a street-gas friendly motor. I also am skeptical about the hp difference with just gaskets being different.

In order to properly "detune" for pump gas, he'd almost surely have to change pistons and for $200, that'd be a little fishy.

To me, at that price, I'd go for a crate motor. There are many to choose from at that price range and with a warranty. Good luck