I have a 1976 Corvette L-82 but the engine was changed out before I bought it. I thought it was it was just a straight swap, 350 for 350, but I decided to run the casting numbers, and if I'm right, its a 68' 327. Also I cant seem to identify the heads that are on the motor.

Any help would be appreciated because at this point I'm not sure what to do with the engine as it was locked solid for about 10 years and I was going to do a 5.3 swap but I was able to get it going and it sounds pretty good. Is there any value in a running 327 from 68'

 

It’s not a 68 Corvette block. I think it’s a 250HP Camaro block with auto trans.

 

Thanks for the help. I'm trying to find out what vehicle it might have come from, also if it is the vin stamped in the front why the 3rd is a number and not a letter.

 

HM was used for 68-69 passenger car 68 327/250 4 barrel auto or 350/250 2barrel auto. the vin on the block stamp is from a 68. and it was cast and assembled in Tonawanda

 

So this could very well be a 350 and no a 327

 

no its a 327 block

 

ok thanks

 

If you're referring to the VIN, every GM assembly plant seemed to have a different format for stamping the VIN derivative, especially before and early on when it first became required by federal law in 1968. The format St Louis used on Corvettes was often different from that used at Baltimore, Van Nuys, Wentzville, etc, for Impala's, Camaro's, etc. Also, some assembly plants were identified in the VIN by a number instead of a letter, such as "2" for St Therese in Quebec and "7" for Lordstown OH.

"HM" had three uses for small block Chevrolet engines:

1965 327/365 with AC, & TI ignition in a Corvette
1968 327/250 with a 4bbl and TurboHydro in a passenger car (full size, Nova, etc)
1969 350/250 with a 2bbl and TurboHydro in a passenger car

To start with we know the engine is not a 65 Corvette 327 because the "T" in the engine code on the pad indicates the engine was assembled at Tonawanda and all Corvette small blocks were built at Flint. That means it's either a 68 327 or a 69 350, but the 3914660 block was only used in 1968, so your engine had to start it's life as a 327 in a 68 Chevrolet passenger car. You can further confirm this by checking the block's casting date, which you can find on the transmission mounting flange on the rear of the block, on the opposite side from where the "660" casting number is. On Tonawanda blocks it will be in the format of a letter for the month, one or two numbers for the day and two numbers for the year.

I don't recognize the head marking, but the only marks I'm familiar with that even look similar to that one were used in the 50's on 283's.

 

you can put a 350 crank in it and build it up to a 350, i always replace everything except the crank on all my engines.....its just a block. If the crank is a forged 327 you can get $200 to $400 for it pretty easily.

 

thanks for the info

 

thanks... looks like the 5.3 might sill be going in

 

still a 327 haha

 

crap... your right lol

 

OK just so I understand... I have a 327 block but could be built as a 350 using longer connecting rods. is there any way of telling if its a 350 without ripping apart the engine.

 

It was born, machined and assembled as a 327/250. 50 years latter who knows what's inside. If you want a 350 block they are a dime a dozen and still being cast today.

 

As for the heads, pull off the valve covers and note the part numbers and casting dates. Look at both as they may not be a matched set. That will get you close to what they started life as – but, like the conn rods, could have been reworked over the years.

 

ok sounds good thanks