Thread: 454 build - what intake and cam ?

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Originally Posted by ceejay

Thank you.. the aftermarket distributor I have is definitely too lose in the block. Without the clamp holding it down, it can shake side to side quite a lot in the block where my old points Delco does not.

Back to my original question....

will a Delco HEI out of a 1977 Chevy Corvette / Camaro 350 fit correctly into my Mark IV 454 block ? are the length and diameter and the oil slot near the drive gear in the correct location ?

I will have to find a melonized gear for it as I'm running a Crane hydraulic roller cam

As I pointed out in Post #84, the GM HEI fits every V8 from '55 through 2000, small blocks, big blocks, all displacements. Chevy used the same shaft dimensions, oil pump interface, and drive gear for everything, so I believe the answer is "YES".

You say "...the aftermarket distributor I have is definitely too loose in the block" but then you ask will a "...Delco HEI out of a 1977 Chevy Corvette / Camaro 350 fit correctly into my Mark IV 454 block." Is your HEI distributor a used GM HEI unit or aftermarket? Define "Too Loose". Have you measured the distributor base on the old point style compared to the HEI compared to the hole in the intake with a pair of calipers? How sloppy is it? Regardless, the "play" you mention sounds like it's the distributor housing base to the intake manifold, not the distributor shaft so it won't affect your timing once locked down. That said, if it worries you at all why not invest $100 in a new HEI unit from JEGS, Summit, or another reputable supplier? Just avoid the Amazon Specials and buy from a good seller. A '77 unit is almost 50 years old!!!

Earlier you questioned the reliability of the HEI units. Back in the early days of electronic ignition the modules in all of the systems were the weak link, and seemed to fail for no reason, but it was usually excessive heat. They've improved through the years, and while a module can still fail the "mean time between failures" is drastically improved. I'm running a GM HEI on the '32 roadster, provided by GM Performance in the ZZ4 package, and I don't bother carrying a spare module. I can get one at any big box (or hole in the wall) auto parts store if it ever does happen to fail. It's just not a worry point to me.

Good luck! It's great that you've got the engine installed, and that you're working towards getting it moving down the road!!