When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
A month ago, I picked up a block that was taken out of a 73' pickup.
Guy had the heads from the block, and he let me take them as part of the deal. The guy I got them from said they could have the intake ports bored to 2.02. The VIN on them is 3998993. Supposedly, these heads were put on low performance cars and trucks. My question is are they even worth keeping? Any one have any experience with these heads?
According to John Lingenfelter's cast iron head chart in his book, you have a set of nominal 76cc heads with 1.94 intake/1.5 exhaust valves. The nominal port volumes are listed as 159cc for the intake and 65cc for the exhaust.
Depending upon the goal for rebuilding the truck block, you can either use them as is (stock), or save the money you would spend modifying them for a set of aftermarket cast iron heads such as the Summit Racing SUM-152123 heads ($649 a pair). These fully assembled heads have the 2.02 intake/1.60 exhaust valves, screw-in studs, nominal 67cc combustion chambers, and a nominal 165cc intake port volume.
Thank you for the info. This will be my first from-the-ground-up engine build. Its going in a 72' 240z. I'm looking for around 350hp, hence my inquiry as to the merit of these heads.
Last edited by nbayZguy; Dec 2, 2005 at 11:49 PM.
Reason: grammer error
According to John Lingenfelter's cast iron head chart in his book, you have a set of nominal 76cc heads with 1.94 intake/1.5 exhaust valves. The nominal port volumes are listed as 159cc for the intake and 65cc for the exhaust.
Although the VIN (casting) number is different, this description is a close match for the "624" cast iron heads used on the 1984, 1985. and early 1986 Corvettes. Unless they need extensive repair work, they are worth what you paid for them. For the investment of a little D.Y.I. time, and a valve job, they could be made to work acceptably. The goal of 350 hp, might be a stretch for them.
A month ago, I picked up a block that was taken out of a 73' pickup.
Guy had the heads from the block, and he let me take them as part of the deal. The guy I got them from said they could have the intake ports bored to 2.02. The VIN on them is 3998993. Supposedly, these heads were put on low performance cars and trucks. My question is are they even worth keeping? Any one have any experience with these heads?
I'm running these on my vette now (stock with the motor), and I've been happy with them. I'm running .125 domed pistons to offset the large combustion chambers, along with 2.02/1.6 valves. The machine shop I worked with suggested keeping the heads since they flow well for large chamber heads (in fact they sell them in their shop for some dirt track applications), around 200 cfm I think.
Back in 1989, a high school buddy of mine built a 400 sb with flat top pistons; his compression was just under 11:1. He had his 993 heads cut for 2.02 and 1.60 valves. He ported them himself. He ran a Crane Blue Print of the Chevrolet solid F/T Off Road cam, with 1.6 stamped long slot rockers. He topped it with a Torker intake and a 750 double pumper. With a TH 350 and a 3000 stall, and 4.10 gears he eventaully got into the 11.9s in his 67 Chevelle. I had a 70 SS 454 that ran 12.7s. He would walk away from me at any speed in any gear.
Better heads are available, but the 993s can be made to do good things.
[QUOTE=wesmigletz] With a TH 350 and a 3000 stall, and 4.10 gears he eventaully got into the 11.9s in his 67 Chevelle. I had a 70 SS 454 that ran 12.7s. He would walk away from me at any speed in any gear.
QUOTE]
Sounds like these heads are a good find! Appriciate the input.