Help choosing a Motor?

[rick0312]

I am at the point in my rebuild where I have to decide on a motor. My truck will primarily be used on the weekends only. I won't be hauling heavy items just some light use back and forth from the hardware store. I have it narrowed down to two GM crate motors. Maybe you guys can help me with my decision. see info below:


#1 350 250h/p
This is a great entry-level replacement engine for older cars and trucks, and a great basic street rod engine. All of the parts in this engine are “Brand New”.

350 Cubic inches 4.00" Bore, 3.47" stroke

8.5:1 compression ratio.

250 HP @4300 rpm

350 ft. lbs of torque @ 3600 rpm

(These Numbers obtained with a Quadra jet Carb, 15/8" headers, and an Edelbrock Performer intake part # 2101)

Engine consists of the following parts:

Block -part # 10066034, casting # 10066036

2 piece rear main seal 4 bolt main

Crankshaft- part # 3932444

Nodular Iron 1985 and older flywheel bolt pattern.

Powdered Metal Connecting rods- Part # 10108688

Cast Aluminum Pistons- part#12514101

G.M. High Volume Pump Oil Pump- part # 12555284

Hydraulic Flat tappet Camshaft- Part#3863151

Intake Lift-.383" Exhaust Lift-.401"

Intake Duration @ .050"- 194 Exhaust Duration @ .050"- 202

Lobe Seperation-112

This cam Has a mechanical Fuel Pump Lobe.

This is a low end Torque oriented camshaft.

Cylinder Heads- part # 14034808, casting #33417369, 1.94" Intake valve, 1.50" Exhaust Valve, 76cc Combustion Chamber, 7 Bolt style Exhaust Flange Standard, 85' and prior intake manifold bolt pattern. Perimeter bolt style Valve Covers. This head is very similar to the old #882 castings from the 1970's

#2 350 290h/p
The HP 290 horsepower will provide great durability because of its 4-bolt mains, PM steel rods, strong cast aluminum pistons.
The camshaft has .450" intake and .460" exhaust lift with hydraulic flat tappets.
The cast iron cylinder heads have 1.94" intake and 1.50" exhaust valves wit 76 cc combustion chamber. These heads have the conventional 90 degree with 12 bolt intake manifold attaching design used from 1955 thru late 1980 12 bolt postion @ 90° to the intake/headflange.
This engine was designed to work with the following components:
intake manifold 10185063.
HEI distributor 93440806.
balancer 12551537.
flex plate 471529.
Bolt on the starter,water pump, fuel pump, and your ready to run.

[463]

http://www.gmperformanceparts.com/ this gm site should give you just a bit more insight to the last moter choice.

[mnunn454]

appears they're both 350's, 4-bolt mains, and 8.5:1 compression ratios that'll run on regular gas. Only major difference I can see is the price and the horsepower output.

If you feel you need/want the extra 40 horses for the diff in price, then I'd say go for it. (I use $10 per HP as my rule of thumb)

My opinion is that once you have it, you're less likely to regret paying for the often un-used 40 horses, than the regret of not having them when you do want them.

[rick0312]

Yea it's about 475 more for the extra 40hp. The 250 motor is $1375 and the 290 is $1850. The cheaper motor produces about 350 ft. lbs of torque @ 3600 rpm. The 290 hp produces
326 lb-ft. of torque @ 3750 RPM . whats better more torgue or greater horse power?....rick

[mnunn454]

For your purposes, I'd think torque was more important than peak HP. But take a look at the two engines' dyno charts on GMPP's website and make sure there's a big diff in torque down low in the normal driving RPM range..

[68C15]

I would go for the first one.

[rick0312]

thanks........Iam going with the first one! MORE LOW END TORQUE!

[Jim_PA]

Yeah, definitely the first one. The 2nd is over-cammed for a heavy truck. A friend of mine put the 290 version in his 81 3/4 ton, and hates it.

[dan42]

I have the first one in my truck, and it runs great. And I got it used.

[lilred67]

i bought the 250hp for my truck last fall. i haven't drove it a whole lot since i got it running, but it runs great and has plenty of power/torque for my truck.

[jb4short]

If your in Eastern PA I can offer you the GM crate motors and you can pick them up here at my place....save freight

[greasy68]

That sounds like a deal. Buy the first one through Tri-ProAutomotive and you will be all set.

[ChevLoRay]

I've had this same argument within the confines of my damaged brain, so I gotta say I appreciate the post and the comments, especially from those who have seat-of-the-pants experience. Thanks.

[rick0312]

wow...great info! thanks so much for all of the input.
Thanks tri-pro...I live in the Doylestown Pa area and there is a dealer about 2 miles from me who will sell the 250 for 1375. I will be purchasing inner fenders, rad core,battery tray etc from you when I am ready. Thanks

[68 short step]

hope this helps

[jb4short]

Originally Posted by rick0312

wow...great info! thanks so much for all of the input.
Thanks tri-pro...I live in the Doylestown Pa area and there is a dealer about 2 miles from me who will sell the 250 for 1375. I will be purchasing inner fenders, rad core,battery tray etc from you when I am ready. Thanks

Fred Beans....say hi to Denny for me...LOL

[ccd3]

I have the 330 Hp GM crate engine. here is my 'seat of the pants' impression:

You can definetly feel the torque drop off at 2000-3000. Easing on the throttle in this range makes more noise than go. However, if you drop the hammer and open the secondaries- things happen in a great big hurry.

In all fairness, I have the spring/diaphram on my Holley-secondaries set more for economy than speed. As is, I get 10-11mpg (driving very conservative) For fun- i ran the spring all the way opposite- the truck was responsive in that range. If you set your carb up that way, I'd guess your mileage would drop to nothing. just running around town and jetting down the highway for about 30 miles dropped my cumulative mileage to 8mpg.

Practically- this engine is probably not the best choice for a heavy truck & daily driver... But it sure is fun

[syncrov69]

<<Yea it's about 475 more for the extra 40hp. The 250 motor is $1375 and the 290 is $1850. The cheaper motor produces about 350 ft. lbs of torque @ 3600 rpm. The 290 hp produces
326 lb-ft. of torque @ 3750 RPM . whats better more torgue or greater horse power?....rick>>

Where you find this engine at this price? Do you have an adress or email?

[Wrenchbender Ret]

I use the basic Goodwrench engine in all my projects & have sold hundreds of them. They run good & last forever. You can,t build one for that cost. Most larger cities have one or 2 dealers that specialize in them. The other dealers buy from them. Shop around . there is no set price & sometimes they tack on other charges. Anyone in the K.C. area I can give you the number of the salesman that handles them.