Another one for the engine numbers guys

[Subfixer]

Got all the covers off the engine today. I know this isn't the original, so I'd like to know what I have. Here's the numbers:

Nothing on the pad. Obviously decked.
Back of block driver's side: 3782870
Back of block pass side: J163
Back of block behind flywheel, Pass side: H22 870 over 812
Front of block under timing cover Pass side: 870 over 721
Front of block under timing cover Driver side: G18

Heads
Pass side: 3782461, 64 over the 78, 91 under the 24, K143 over 13
Drivr side: 3782461, 64 over the 78, X under the 61, K93 over 13

All numbers on the Block & Heads are raised castings.

Thanks.

 

[61 Silver]

Engine Numbers

I take a stab at your numbers:

I believe that it is a 1963 Corvette block used for all engines reguardless of HP.

The casting date: 10/16/63

Heads: 327CI for 300, 340, or 360HP

casting date:
Right 11/14/63
left 11/09/63

Do you have the casting number for the intake and the thermostat housing?

Ray

How did I do John Z?

 

[Subfixer]

Intake is 3844459 Date K133
Thermo housing 3827369 B3

 

[61 Silver]

engine numbers

The intake is for a 300Hp Corvette engine dated: 11-13-63. If all you date codes end with a single number, 3 instead of 63 then they were cast in Saginaw and are of Corvette origin.



I will have to check a few more books on the thermostat outlet. The 63 JG only states the numbers are stamped in and not raised. It does not confirm the part number. It should be Cast Iron.



Ray

 

[Subfixer]

Thermo housing is cast. Numbers are not raised in the housing, but are not stamped either. Numbers are sunk in cast.

The intake date matches the original 870 shortblock date I have in storage (K133). The pad on that block also has the correct VIN and HP code. Apparently, a previous owner tried to match the date of the replacement shortblock as close as possible.

The only question remaining for me is the heads. I am going to assume they are 1.94/1.5 heads which will be fine for my needs. What was the difference between the 461 and 461X heads? Since it looks like I have one of each, will this cause me any problem?

 

[JohnZ]

There's a very minor difference in intake port flow between the 461 and 461X - won't make any difference. Those castings were used for both the "large" and "small" valves - just machined differently. When machined for the 2.02"/1.60" valves, an additional cut was made on the side of the chamber to unshroud the intake valve for improved flow; many were converted later from the small valves to large valves, and if the additional cut wasn't made to unshroud the intake valve, they flowed less than they did with the original 1.94"/1.5" valves. Here's what the additional factory unshrouding cut looks like.

 

[Subfixer]

Thanks Ray and John. Looks like I'm good to go.