And along those lines....

[Kevin Riel]

The reason I'm asking for cam specs below, I'm reblocking (correct block) my '59 with a correctly dated Powerglide block. (I currently have a three month too new manual tranny block). This engine will be 0.60 over. Would the 300 hp. cam idle similar with a bit more punch, or would it be OBVIOUSLY noticable?

Kevin Riel

[Chuck S.]

Re: And along those lines....

Kevin, if it were me, I would not commit a lot of money and effort to a block that is 0.060 over, and I sure wouldn't bore one 0.060 over. You should only bore over the smallest standard size that will clean up the bores. Also, overboring to gain displacement is insane; maximum overbore, i.e. 0.060", only gains you about 5 cubic inches...not worth the compromises and problems that much overboring can bring you

At 0.060 over, you essentially have "but one life to live" with that block, because oversize pistons are, to my knowledge, not available above 0.060 over. Once the engine gets tired again, or something goes wrong and you score a cylinder wall, your 0.060 over block will be likely be history.

I think Duke Williams said recently that the OE 300hp cam is undetectable.

[Kevin Riel]

Re: And along those lines....

Chuck,

I follow along with you. The only thing is, this is the PERFECT block for my car. The assembly date of the block procedes the build date of my car by less than a week. It has the proper suffix. It is NOT a restamp, but the real deal. For me, as the last piece of the puzzle to make a "numbers matching" car, I'd sleve it if I had to. It's worth it to me. Which, by the way, would be my course of action if by chance I put enough miles on it to need to rebuild/rebore it again (which is very unlikely). I have to bore it .060 in order to clean a couple of the holes. Bubba got a hold of it with a ridge reamer at one time. I'd like to have seen how much oil this thing burned when they took it out of the last car it was in! Thanks for your input!

Kevin Riel

[Jim Mitchell]

Re: And along those lines....

Kevin,

I would have no reservations with the .060 overbore in your early 283 block. The old 283 blocks had fairly thick cylinder walls. They were routinely bored .060 and lived well onboth street and drag strip. Many of these same blocks were bored to 4", thus yielding 301 cu. in. The 4" bore worked okay, but overheating was not uncommon. Street life was marginal.

I personally built many .060 early 283s and experienced no problems whatsoever. I drag raced a 3600 lb car with this overbore back in the late '60s/early '70s and ran low 12s on a regular basis. After I quit racing, I sold the short block assembly to a friend for his '57 Chevy stationwagon. This car was a daily driver and the block is still going strong (now in a '67 Camaro).

My 1960 Vette has a .060 block in it with the 350 hp 327 cam in it and I love it. As was previously stated, the 300 hp cam is a good choice. Idle quality should not change from the original cam. Good driveability, too.

[Justin N.]

Re: And along those lines....

Kevin,
I had to take my 67 block .060 over also. It is the original motor for my car with the correct numbers. I was told when I purchased the car that the motor has a fresh .030 over bore and hadn't been 'broken in' yet. I pulled it apart anyway, as the car had been sitting for about 12 years previously. The bores were so badly scratched and the misaligned, I had to take it from .030 to .060.

I had to sleeve a block once because it was a 'K' code block for my 65 Gt-K Fastback. I went .040 over with a sleeve and it ran strong. I also had Larry Ofria do the machine work at his shop in Northridge Ca: Valley Head Service. He IS 'bar none' the most experienced machinist I know in the L.A. area. He was grinding out heads for Carrol Shelby back in the early sixties out of a converted chicken coop, where his shop still resides today. I don't know where you live, but if it's close enough, I'd trust him with anything!

Justin #41362

[Dale S.]

Re: And along those lines....

It never ceases to amaze me how these old drag racer names, and racer's keep popping up on the thread. Drag racers,& Corvette's, there is a connnection. There is some thing in the blood. Dale

[Dick W.]

Re: And along those lines....

Larry did excellent head work in the late '60's and early '70's. I had a few sets of his reworked cylinder heads

[Chuck S.]

Gotcha. Makes Sense.

I just wanted to make sure you knew what the 0.060 overbore implied. Not where you want to go on a collector engine if you have any other choice.

My 70 had "just been overhauled" when I bought it (yeah, right), but seemed listless. It just didn't seem to run like a Corvette. I decided to freshen the engine up as part of the body-off resto...found the bearing inserts showing copper and the bores 0.060 over. The bores were sloppy and my rebuilder would like to have overbored it more (not an option), or sleeved it, but that was a little more money than I wanted to sink into it.

I had him build it back up with SealedPower rings after he worked some black majic on the old pistons. Now its a judicious crusin' motor and definitely not a drag racing motor. A GM performance crate engine is likely to be in the car's future once I get it judged.

[Jim T.]

Re: And along those lines....

Jim what is the compression ratio of the 283 .60 over in your 60 with the 327/350HP cam?

[Jim Mitchell]

Re: And along those lines....

Since I am using flat top, 4 vlave relief pistons with the stock heads, my best guess would be 9.0:1.