Has anyone used this particular GM HO crate engine with any success? The part # is 12499529 350 ci 290 hp 326 tq. Many thanx............

 

what do you want to do with the car? What are your goals and plans?

 

This engine is going in my 1986 GMC 4x4 Suburban. I did not mention that because it is not 3rd Gen related. thanx for the reply..........

 

For driving and towing it'll be fine. For a performance build it will be a turd.

 

I would go with the 260 HP 350 over the 290 HP for towing. The cam in that engine is way TOO large for its 8.5:1 compression ratio and 1.94/1.50 (882 style) castings. That cam likes compression and good flowing heads. 326 ft/lbs is nothing for a 305 much less a 350.

 

The advertised compression for the engine is 9.5:1.

 

Not from what I have seen.

Horsepower: 290 HP @ 5,100 RPM Torque: 326 FT/LBS @ 3,750 RPM
Displacement: 350 C.I.D. Bore / Stoke 4.00” / 3.48”
Max. Rec. RPM: 5,100 RPM Comp. Ratio: 8.50:1
Heads: Cast Iron, 76 cc Valves: 10093027 - 1.940” I, 14095451- 1.500” E
Camshaft: 03896962 Hydraulic Flat Tappet
Camshaft Lift: .450” I, .460” E Duration @ 0.050": 222° I, 222° E
Lifters: 05232720 Flat Tappet Connecting Rod: 10108688 Powdered Metal
Block: 10066034 - 4 Bolt M., Iron, 2-piece S. Pistons & Pins: 12514101 Aluminum
Crankshaft: Cast Iron Nodular, 3.480" Stroke Piston Ring: 12507985
Rocker Arm: 10089648 - 1.5 Ratio Stamped Steel Head Gasket: 10105117
Oil Pump: 12555284 Oil Pan: 10066039
Ignition Timing: 34° BTDC total advance. Fuel: 87 Octane
Spark Plug: R45TS, Gap @ .035 For Points Distributor or .045 For HEI Distributor
Technical Note: Distributor with melonized steel gear MUST be used with steel camshafts or engine damage will occur. GM recommends their HEI distributor P/N 93440806 if you need a complete distributor and not just a hardened gear.

Sallee Chevrolet - Performance Parts Catalog

 

Go to crateenginedepot.com and click more information...................

 

I just got that engine put in my 85 iroc and it runs great. im still in the break-in period though but the car is definatly a ton stronger than that 305 that came out. i got mine from paceperformance.com check it out.

 

Don't believe everything you see on the internet. Do believe in fat fingers.

I do see "wit 76 cc combustion chamber", which says "low compression" to me (and that their webmaster has typing problems). I'll believe the 76cc chambers because all of the other sites say that, but not the 9.5:1 CR.

 

I have torn one down for a vortec head swap. The compression calculated out to 9.5:1 with vortecs on it. Vortecs are 64 cc chambers or about that. It definately had the bath tub 70s style 76 cc heads on it. That makes it around 8.5:1. In reality that engine is the 260 HP crate 350 with a L82 cam in it. Chevy High Performance calculated 7.8:1 compression in their 260 HP 350 crate.

 

if you look at the pistons that it list as the crate motor having there is a very slim chance that its making 9:5 compression with 76cc heads. The pistons are listed as making 9:1 compression with 64cc heads, which makes them more then likely 11-13cc dished pistons.

 

It also depends on how much compression height there is. The engine that I took apart was .015" in the hole. Most manufacturers rate compression ratio at zero deck.

 

I could not find the piston # in GM performance parts maybe I'll check again. But for 1700.00 to pickup I bought it so now its a moot point.

 

You'll be fine. I think you are looking for something bullet proof and with compression that low, your motor will outlast the truck. Well maintained L48 Corvettes from the 70s routinely show near factory compression- even though they are between 25-30 years old.

For a stump puller or daily driver you'll be just fine. Like other folks have said- you'll be hard up to try and race the truck- but I get the idea you aren't into racing it.

Let us know how it goes!