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 1959-1979 Big Pontiac Tech
 400 with early heads and intake
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paxton
Tribal Scout

19 Posts

Posted - 10 Sep 2013 :  12:02:45 PM  Show Profile  Reply with Quote
I did the search but no cigar. What I want to do is put the 64 and back heads and intake on a 73 400 just for eye appear. (blindness) Actually I have everything but I know there are some do`s and can`ts with the swap. Thanks

Mr. P-Body
Running Bear

USA
2258 Posts

Posted - 10 Sep 2013 :  6:59:37 PM  Show Profile  Visit Mr. P-Body's Homepage  Reply with Quote
Paxton,

It's a straight-forward "deal". The valve angles are different, so if you have more than about .440" lift, you may want to use those butt-ugly 8-relief pistons. You can turn a small dish in them to lower compression, and get the 19 deg. valve relief at the same time. Pushrod lengths are also different, but the '64 length is available in a "hardened" version for little money (about $45 a set, maybe 50). If the guide slots in the heads are okay, the stock pushrods (389) will be fine with stock springs.

389 rockers are also a little different. Later heads, all sizes of engines, the rockers have a "dimple" in them between the fulcrum and tip. The "early" head valve angle uses those without a dimple. Don't try Chevy stuff, it doesn't fit. They're still avalable "new" from Melling. If you have the correct '64 units, use them as long as there's a hole for oil to come through from the pushrod. SOME '64 "big car" engines still oiled through the stud (bad). Those rockers won't have an oil hole. 400 rockers "work" but don't "fit". Maintaining a non-adjustable valve train (desired for flat hydraulics) can still be done with all the correct parts.

Not much else is different in the sense that it needs attention to perform correctly. The "closed" chamber likes a little more timing (total) than the later ones. Changing from 4Xs to 389 heads, even if you lower the compression to 9:1 or so, will surprise you. With a relatively mild cam, the car will run harder. Stock 4-bbl. intake? AFB or Rochester? Edelbrock used to make one called "EP-4B". Good intake for those heads. They show up at swap meets often. None made new in at least 25 years, maybe longer.

A friend and I combined "stuff" in the mid '70s, which included his '70 Malibu and my '72 400. He had '64 heads and that intake, and I had a 750 Holley. Used a Crane "Blazer" (forget now, somewhere around 224 @ .050, .470-ish lift) cam, and called it "MaliGoat". Took a bit of money from local small block guys 'cuz all they looked at was the valve cover and counted bolts. That it wasn't even a Chevy NEVER occurred to them. The fender still said "307". We never lied to anyone about it, but no one asked until AFTER the race...(:- They would ask if it was a big block. "No." True statement. So the hood never came up 'til it was too late. Even then, few ever recognized it, but the REAL racers. Laid waste to many a 350 and 400SB Chevelle. Circa 1976-9, San Bernardino. Never got to the track. With sticky tires, I'm sure it was a 12 second car. My Judge was then, and the MaliGoat would run along side until about 100. Once word got around, it was no longer effective as a sleeper.

Jim

Edited by - Mr. P-Body on 10 Sep 2013 7:05:08 PM
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paxton
Tribal Scout

19 Posts

Posted - 11 Sep 2013 :  4:53:10 PM  Show Profile  Reply with Quote
Thanks Jim. Really great info. Now to find a pair of 716 heads and "copy" your success. A sleeper tempest with an olde goat driver.
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