I have a '71 vette I am trying to sell with a block with a casting number 3963512. There is no"P" under this number. The buyer is concerned it may have a replacement block. The date when block was cast looks like l 8 8 or l 8 9. This is on the rear of eng pass side. Is there a date when engine was assembled and where might that be???
Casting date shows 68 or 69, depending which number it is. This is too early for a 71 car to have this engine casting date. On the front of the engine, under the passenger head there is a stamped pad that shows VIN of car and type application for that engine and the assembled date. Is that there????? If so print here all numbers stamped. Just by the casting date my opinion is the block at least is wrong...............B
Drivers side 3963512 No "P" underneath this number. to the right of this number are the symbols exactly as I have written them.
GM
1
CONV1
On the passenger side, I see 8 8 1(still a prob, car built 01/71), I guess I read them upside down before, this number is directly under the dist, should the cast date be closer to the cylinder head.
On the pad c11s1XXXXX(matches vin)
T0105CPH
Car is a 365hp manual.
I bought car 10 years ago and looks original to my untrained eye.
What do these broach marks look like...
Last edited by Rayzz; 06-18-2007 at 02:44 PM.
Reason: add info
1. You don't need a "P" underneath the casting number ...
2. The casting date is located on the passenger side, lower part of the engine by the starter - sounds like you have some other numbers there.
3. T0105CPH = Tonawanda, January 5th, 454/365hp with 4 speed (LS5 with manual)
4. Broach marks are minute parallel factory finishing marks "carved" into the face of the block before it was stamped.
5. Sounds like your VIN would be around 09000'ish ???
I thought '71 casting dates were on the to of motor,,,where it meet bellhousing for transmission??
I dont see any # by starter, any more hints yo can give this rookie
The 3512 block started out with the casting date on the passenger side just forward of the starter, but it was moved to the bellhousing flange in late 1969.
Only early 512 blocks from 68 are dated down by the starter, his date location is correct. Sounds like the block is right, only thing is, is it earlier than the tag inside the door assembly date?!?!?!?!?! As long as the VIN on the block matches and the body tag jives, I see no problems..............................B
actual vin is
194671S106854
build date 01/71 i believe 01/18/71
casting date from left to right (sitting in pass seat) 1 8 8 or 1 8 9
could a block cast in 68 an not be used for that long a time??
The first digit would normally be a letter, so either I (eye) or L, for September or December. (But there are examples of all numeric codes also ...)
If it were a 1969 date, then the cast date would be down by the starter.
So I think you have a quandary here ... ???
September or December of 1970 would work well. Any chance that last "8" or "9" is really a "0" (zero) ?????
I looked at that number more times than I care to today. It could be a 0 but there is a line in bisecting the zero. Anyway the buyer came around again today and we agreed on a price.
The first digit would normally be a letter, so either I (eye) or L, for September or December. (But there are examples of all numeric codes also ...)
If it were a 1969 date, then the cast date would be down by the starter.
So I think you have a quandary here ... ???
September or December of 1970 would work well. Any chance that last "8" or "9" is really a "0" (zero) ?????
Only early 69 prod blocks made in 68 were dated at the starter!!!!!
I also thought casting dates after 69 were double digit for the year, example.71, 72, 73
If your engine is original, a derivative of the VIN will stamped on the pad at the front of the right head. You should find 11S106854. This stamping will be smaller characters than the engine identification stamp.
Only early 69 prod blocks made in 68 were dated at the starter!!!!!
I also thought casting dates after 69 were double digit for the year, example.71, 72, 73
They are. I've had 3 '70 LS5's, 2 '71 LS6's, 1 '71 LS5, all had a two digit year code. Something is a miss here.
Corvette Store
1971 LS5 Block question
