Thread: 72elk

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The Performer EPS will leave 40 hp on the table, over a Performer RPM. The RPM, NOT THE AIR GAP, will make more horsepower and torque from 1500 to 6000 than any other intake manifold. I've seen this hundreds of times and it is dyno proven. The AIR GAP is a race piece, the RPM is a street piece. I have had many reports of fellows who have used the Air Gap on the street and have suffered drivability problems. When a motor is street-driven, it needs a great deal of heat in the intake manifold to help break down the large droplets into a mist so that they can be burned in the combustion chamber. If the manifold is cold, as it is in the Air Gap model, there is insufficient heat to help break down the fuel/air mixture and drivability suffers, with the driver encountering lurching and coughing. In a race application, this is not a problem because the motor is going balls to the wall throughout the rev range, velocity is high all the time and keeps the mixture homogenous.

The design of this RPM intake was first used on the 1968 Z-28 302 and has proven to be the best street intake there is. It was so popular back in the day that Edelbrock cast up the 7101 Performer RPM from the design. Holley followed with their offering, the 300-36 Street Dominator and Weiand jumped on the bandwagon with their 8014 Stealth offering. Competition Products came along a little later with their 52021 Typhoon. The Typhoons are no longer available new either, having been replaced by the Hurricane Air Gap model. If pressed for my choice of used manifolds, I would use ebay, craigslist and Hemmings Motor News to try to find a used 300-36 Holley Street Dominator, with the Weiand 8014 Stealth running a close second. There is another choice that is available new, the Weiand 8150 Speed Warrior, that I would use without question. It's not quite as tall as the 8014, but will do a great job in street duty.

You will not need a 750 carb to make 300 horsepower, but you will need one to make 500 horsepower.

One of the other things that a lot of rodders miss is squaring up the block. If all the corners of all the block decks are not equidistant from the centerline of the crankshaft bores, then each cylinder will have a different static compression ratio and a different squish/quench dimension. Not only that, but the heads will not sit squarely on the block and it becomes hit or miss to get the intake manifold to seal up on the heads. Occasionally, you will see this manifest itself as oiling one or more cylinders from the bottom of the port, where a gap cannot be seen or found with a flammable product. Speaking of squish/quench, we generally shoot for 0.035" to 0.045" to make the motor bulletproof from a detonation point of view. There are lots of small things to consider that many fellows simply do not know to check when building a motor. You may know all this stuff, or you may not. Either way, you are in good hands with this group, we have your best interests in mind.

You might get this build started off by furnishing us the block casting number from the rear drivers side of the motor, just in front of the flange where the bellhousing bolts on. Then, the suffix number, which is on the passenger side of the block, just in front of the front of the cylinder head, very close to the top water pump bolt head on the passenger side. Finally, casting numbers from the heads will help, and can be found under the valve covers, cast into the heads between the valves.

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Haven't been able to find casting no yet but the no stamped on the block below the alternator is 1m1226 with a stamping below that of IVP. Based on the small block Chevy engine code the 1m stands for a 1969 350 - 255hp with 9.1 compression. My compression readings are 4@135, 2@138 and 2@140 which coincides with the published CR.

Head stamp is 83417369, Hencho in Mexico. I believe these were used with gm crate engines and have 1.94" intakes and 1.50" exhaust.

I really have no idea what the cam is other than its aftermarket and has a moderate lope at idle.

Hope this helps and thanks for the suggestions on intakes.

Nice, Elkie's are always cool. I had a 72 and a 75; both great cars.

Originally Posted by States

Haven't been able to find casting no yet but the no stamped on the block below the alternator is 1m1226 with a stamping below that of IVP. Based on the small block Chevy engine code the 1m stands for a 1969 350 - 255hp with 9.1 compression. My compression readings are 4@135, 2@138 and 2@140 which coincides with the published CR.

Head stamp is 83417369, Hencho in Mexico. I believe these were used with gm crate engines and have 1.94" intakes and 1.50" exhaust.

I really have no idea what the cam is other than its aftermarket and has a moderate lope at idle.

Hope this helps and thanks for the suggestions on intakes.

The head casting number is 33417369, 90-up...350...Gen.I.... Goodwrench crate motor,"Hecho en Mexico", 76cc
With 76cc combustion chambers and the need to run this motor on 87 octane unleaded fuel, I'd bet the piston crowns are 10-12cc dishes and the static compression ratio is more like 8.5:1. Please do your part for humanity by removing the heads and smashing them with a sledgehammer so that some other lad down the line would not unsuspectingly try to use them on his hot rod.

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There has been some discussion here regarding head stamp. Many people have said the the first number is a 3. I had three individuals look at my heads and also used a magnifying glass (moving up in years ya know) and it is diffently an 8. One person on the board indicated that they were good heads. This determination is beyond my knowledge. Just as a note, I've been running 91 octaine and plan on doing that as long as I can find it. I run it in all my Harley's so I'm used to buying it.

Pardon me for taking so long to reply, sometimes things need to rattle around in my brain before I make a decision. So I need to ask, can a good set of heads be bought for around $1,000? If not, without going crazy, how much would a good set cost and where should I look?