SBC Interchangeability???

[Bob S.]

[John H.]

Re: SBC Interchangeability???

You'll want to use a '68 or earlier block with the crankcase vent hole at the rear in order to use your current PCV system parts; if you use a later block, they don't have that hole, and you'll have to use a non-original arrangement for the PCV system.

Vitually everything else will interchange, including your intake, as long as your 350 replacement doesn't have Vortec heads.

[James G.]

Re: SBC Interchangeability???

If I had my original engine, I would rebuild it. You will lose 15% value in installing a service relacement engine.

Now that being said, all 327 engines used between 1962 and 1968 and later will work. Your pullies will not line up if you use a smaller HP engine as the thinner crank dampner was used. Everthing else should bolt up.

1969-70 350 engines #3970010 were excellent upgrades to these cars in the early 70's. One of my 57's used its original 283 then a 63 larger 340/327 and finally a LT-1 big 370/350. That LT-1 made the car scream.

When I sold the car in 1979, the new owner said, "To bad you don't have the original engine. I'd pay you $500 more" And in those days $2500 for a 57 was a lot of money.

[Joe R.]

Re: SBC Interchangeability???


Hi Bob:

I have been looking into the same question for my 67. I'd like to build an "expendable" short block that I can run hard without fear of damaging the original block.

In my case, I want the engine to look correct. If this is important to you, you must follow John Hinckley's advice and use a block that has the PCV intake vent hole in the back, next to the distributor. If the block does not have that provision, you will not be able to use stock valve covers without performing some complicated modifications on the intake.

I thought the last year for the vent hole was 1967, but John's post says 1968.

If you are not concerned about casting numbers, there are probably millions of 327 blocks that have the required vent hole. The only 350 block with the vent that I know about is the 1967 Camaro 350 block. These blocks are not cheap because all the Camaro guys want them.

I don't know about 1966 Corvette blocks, but for 1967 the same block was used in Corvettes and passenger cars. If this is true for 1966, you could probably find a passenger car 327 block with the correct casting number and casting date for your car. Then you could still have it judged and lose only 50 points for having the wrong numbers stamped on the pad.

[Bob S.]

283 cylinder wall thickness?

Thanks for the great input.

I'm also wanting an expendible engine to replace (at least temporarily) the original L-79.

I think I have a local lead on what's described as a '63 283 engine.

I searched and found a post stating the "early" 283's had sufficient wall thickness to allow overboring to 4.0+", but "later" 283's were cast with thinner walls (i.e. like the 327) limiting overbore to around .060".

Anyone have a good idea when the casting change to the 283 cylinder wall thickness occurred?

Bob....