Early 1956 cylinder case

[Bernard M.]

I was recently asked to comment on the suitability of a 265 block for use in a 1956 Corvette. Since it was a Tonawanda issue part, the short answer was simple: NO. However, I was wondering, the vehicle in question is a very low serial number and should probably utilize a first design motor. Since these had a dip stick that entered the oil pan, was there a different casting for these blocks without a hole for a dip stick tube? Was some version of the earlier (1955) design 265 block used? Even the 1955 style block had a dip stick tube in the block, didn't it? Just curious, can someone enlighten me?

[Robert Willis]

Re: Early 1956 cylinder case

All of the 55 and 56 265 blocks that I have ever owned had the dip stick passage in the block. Flint , Tonawanda and Canadian blocks. Bob

[Bernard M.]

Re: Early 1956 cylinder case

Bob, The first few hundred 1956 Corvettes had a dip stick tube on the RIGHT side of the engine. The tube extended from the oil pan. It's these blocks that I'm curious about.

[Robert Willis]

Re: Early 1956 cylinder case

I know about the early 56 blocks in the Vette. I don't think that G.M. revised the block for this useage. I would assume the passageway was pluged with a welch plug or something similar . This also happened with the 305s in a 79 or 80 Chevelle that had the dipstick in the pan. Bob

[Joe L.]

Re: Early 1956 cylinder case

Bernard-----

The 1956 GM #3720991 cylinder block castings all had the provisions for the oil dip stick tube in the casting. So, either one of 2 things must have been the case for the early 1956 Corvette versions that used the pan-mounted dipstick tube:

1) the Corvette blocks were not machined for the dipstick tube, even though the provisions for it were present on the casting. Remeber that the blcok CASTING number is just that; a CASTING number and more than one FINISHED block part number (and configuration) could have been machined from the same casting; or

2) the dip stick tube hole was machined into the block but was plugged in some way

[Garry Barnes]

Re: Early 1956 cylinder case

Where there any distinguishing differences between the "56 #991 blocks used for corvettes versus passenger cars?

[Joe L.]

Re: Early 1956 cylinder case

Garry-----

Not as far as I know, except, of course, for whatever the "sealing method" was for the dipstick tube on the early Corvette blocks.

[ROB DAME MEM# 36211]

Re: Early 1956 cylinder case

I have a Feb. 20th block and the dip stick shaft is pluged
with a sort of steel welch or freeze plug. The plug is inserted
so that it's flush with the block when banged in.
Hope this helps. Rob