heads set up

[72vette]

I have 72 corvette with base engine, looking to put 71-72 LT1 heads on that had 2.02 - 1.60 75cc which had 9.0:1 compression ratio. What does Dart offer for a comparable head like that, and do they offer cams ? Thank for any help.

[BIG CHIEF]

Hello,

By base LT-1 do you mean stock 350 ci ? let me know and I will choose a good head for your set up.

Thanks,

~M

[72vette]

Big Chief , my engine in vette is the base 350 (200 hp) 4 speed , want to put the option LT1 package chevy offered in the corvette 350 1971 and 1972, with 9.0 compression , 75 cc 2.02-1.60 valves. Mine has 8.5 compression, so I think the 75 cc with 9.0 compression that was in the LT1 (71 AND 72) will work with my pistons and be a big improvement with the bigger valves. Also need to find out what cam was in the 71-72 LT1 vette I think it was but not sure mechanical cam & lifter Duration.050 Int:242, Exh:254. Valve lift, Int:459,Exh:485 ,1971 350 330HP LT1, 1972 350 255HP LT1. Not sure if I want to be bothered with constent valve adjustments on mechanical cam versus hydraulic, up for answers on this. Thanks for any help, Bob.

[Awesome Bill]

You should just go with the smallest port Dart offers, I think that is a 160cc port. You won't get much more power from something with 75cc either. You will only have 8.25/1 compression.
We just done a customers 72 350 200hp. We put the Keith Black small domed pistons in, decked heads (487X castings 1.94/1.50, some of the best heads produced @ 78 real cc's) block and come up with real 10.04/1.
We dynoed it for the customer Friday, he was there from start to finish and with a retro Comp Cams roller lifter hyd cam, 4.030" bore, balanced, good valve job, Comp Springs, 34° total timing with HEI Performance distributor OTbox, Edelbrock Performer, 580 Street Avenger, Roller Rockers and good Manely .080" wall push rods, we cranked out 363 @ 5100 with 421 ft lbs torque. Not bad for OTbox tune up. So the key is compression, camshaft decent intake and small carb. Take it from here.
We will be dyno testing his Quadrajet Monday along with his stock single point Distributorl. Will be a nice comparison being he is paying me to do this. I will let you guys know what we get if you would like.

[BIG CHIEF]

Thanks Bill !

165 cc Iron Eagle SS ( Street/ Strip ) is what he is refering to.

PN # 10021171

( 165cc x 1.94 x 1.5 Strait plug 72 cc chamber 1.250 spring good to .510 lift )

~M

[72vette]

Thanks Bill !

165 cc Iron Eagle SS ( Street/ Strip ) is what he is refering to.

PN # 10021171

( 165cc x 1.94 x 1.5 Strait plug 72 cc chamber 1.250 spring good to .510 lift )

~M

BIG CHIEF,

Can I get that with 2.02 x 1.60 strait plug 72cc, and what size cam do you recommend for ( Street/ Strip)?

[Awesome Bill]

the larger valve on your block will actually give up hp over using the 1.94. Put it on the dyno and you'll see. Those heads work killer with the 1.94/1.50, it keeps the air speed up and with your little bore, the 2.02 will not off anything but very top end power. If you have the 165 cc heads done with a little work, you will be amazed with the power of just adding the 64 cc let alone the velocity these heads make on engines up to 400 in in street trim. Don't overkill. most people make the same mistake. BIG

[72vette]

The 487x chevy head was actually 2.02-1.60 , the 487 was 1.94-1.50. So to recap what I think you are saying the 1.94-1.50 flow better than the 2.02's and will give me better performance, and go with what size cc, 64, 72, 75. Keep in mind I would like to keep my pistons and just go with new cam and heads.What size cam do you recommend? I have a Edelbrock performer manifold on the car.

[Awesome Bill]

Customers GM Quadrajet was messed up and needed repair, we did not get any #'s at all. He did not want to do any further testing. Sorry. but, the engine still ran very well with the stock heads and raising the compression to a real 10/1

[72vette]

The 487x chevy head was actually 2.02-1.60 , the 487 was 1.94-1.50. So to recap what I think you are saying the 1.94-1.50 flow better than the 2.02's and will give me better performance, and go with what size cc, 64, 72, 75. Keep in mind I would like to keep my pistons and just go with new cam and heads.What size cam do you recommend? I have a Edelbrock performer manifold on the car.

[Awesome Bill]

well you better call GM and tell them they missed one. The 487X stock 1972 castings were 1.94/1.50. I know for a fact because they got new guides, valves, springs etc. What I said about the 2.02/1.60 valves was that you do not have to have them in the 165 heads to make great power. People get really stupid when thinking of valve size and power. Personally, I will use a smaller set of valves to keep air speed and proper under the seat dimensions than most. Big is not always better and most cases worst. Becareful of people telling you that stuff. Most are just to sell something. The 165 cc 64 cc chambers would be really nice with flat tops. This will yeild 9-8/10-1 and be perfect for the street. The head will make plenty of power either way you want to go. Comp cams 280/480 Magnum is the very largest cam I would use and nothing bigger. I will work with a little stall very well and still maintain driveability.