What engine do I have in this thing?

[mikeumkc]

My '70 L46 corvette arrived yesterday. I am very discouraged by what I have found when looking in the engine compartment. The casting number (3970010) is correct, however I have come to realize that they used that number for many 350 engines from 69-80.

Next I looked for the pad towards the front of the engine that would have other ID numbers stamped on it. The engine in my car has no pad. The pad itself is not there. From pictures of other people's cars I see there should be a metal pad that is an extension of the block beyond the head. The pad is about 6 inches long from what I can tell from pictures. I have a very small area (1.5-2 inches) of "pad" that has nothing stamped on it at all.

Any ideas? What else can I look for?

 

[bossvette]

Welcome to CAC
when an engine is rebuilt the numbers are often machined off the pad which is the size of yours, about 2". You have either a rebuilt or replacement engine.
Post some pictures. That casting number is quite common and comes in 2 and 4 bolt versions.

 

[mikeumkc]

Welcome to CAC
when an engine is rebuilt the numbers are often machined off the pad which is the size of yours, about 2". You have either a rebuilt or replacement engine.
Post some pictures. That casting number is quite common and comes in 2 and 4 bolt versions.

Are you sure the entire engine pad on the 350 where the numbers are stamped is only 2" long?

 

[bossvette]

Are you sure the entire engine pad on the 350 where the numbers are stamped is only 2" long?

not a ruler but the best I can do tonite

 

[Vettehead Mikey]

I've spent most of my adult life trying to pretend that 2" was really 6". :crazy

 

[gmjunkie]

I've spent most of my adult life trying to pretend that 2" was really 6". :crazy

Don't try to run 2-20's, You'll Short out!! otfl

 

[mikeumkc]

Not quite the response I was looking for.

 

[mikeumkc]

not a ruler but the best I can do tonite

What year is that engine? I thought the pad on the '70 was much larger. Like the pictures here:

http://corvetteforum.net/c3/1970registry/mechdetails.html

 

[Vettehead Mikey]

Later 0010 blocks have a 2" stamp pad, earlier have a larger (maybe 4"?) pad. I'm not sure what year it changed over but maybe 1979ish.

Your '70 originally typically had an engine with a larger pad, so this does not appear to be the original block.

I don't suppose this is the response you were looking for either.

 

[mikeumkc]

I don't suppose this is the response you were looking for either.

I just want to know what it is, and how to identify it. There is something cast in the area of where the date code should be, but I can't read it real well with all the grease and stuff. It is on a slightly raised, elongated oval...if I had to guess, it says E237....which I would translate to May 23, 1977 if it is in fact the date code I am looking at.

 

[mikeumkc]

The engine in my car appears to have the same size "pad" that is pictured above. Is there any way possible that this is still an engine from 1970?

 

[mikeumkc]

I just talked to the previous owner....he said that he had owned it since 1996 and that he bought it from the original owner who was a girl that he worked with at the time. She bought it new as a leftover in 1971.

He said that she had the engine rebuilt, but never replaced.

With the stamp pad what it is.....is this possible?

 

[JohnZ]

The "short" stamp pad (1-3/4" to 2" long) was phased into the lightweight 350 block castings beginning in 1975, and all had them by 1978. Any 350 block cast prior to 1975 has the "long" stamp pad.

 

[fine69]

Welcome to CAC
.......................That casting number is quite common and comes in 2 and 4 bolt versions.

Is it possible that some years of the L-46 engines had 2-bolt mains, or did they all have 4-bolt mains?

 

[Crimson Thunder]

All the Vette small blocks in 70 were 4 bolt mains so i assume the same was for 69. 71 was the first year for 2 bolt mains on the base motor.

 

[Jack]

The "short" stamp pad (1-3/4" to 2" long) was phased into the lightweight 350 block castings beginning in 1975, and all had them by 1978. Any 350 block cast prior to 1975 has the "long" stamp pad.

Short pad don't bode well for original 1970 ... but I agree w/JZ ... short pad can't be a '70. Maybe it don't have very high CR either. Pull the VCs ... what are its head casting #'s & date codes?

*edit* short pad w/ no numbers ... it's probably a later block that's been decked.

 

[BarryK]

Short pad don't bode well for original 1970 ... but I agree w/JZ ... short pad can't be a '70. Maybe it don't have very high CR either. Pull the VCs ... what are its head casting #'s & date codes?

*edit* short pad w/ no numbers ... it's probably a later block that's been decked.

if the block isn't original there is a good chance the heads aren't either or possibly swapped from the old block onto the replacement block, etc.
besides the casting number that he has already listed there should be a date stamp on the block - that will at least tell what year the block is from to know for sure if it's a replacement as suspected.

 

[mikeumkc]

Ok, I will pop off the valve covers sometime soon when its not 100 degrees here. I guess the consensus is that it isnt an original block, and I agree. So, how much money do you think it would take to get a 1970 350/350 corvette engine that I could put in there to make it a correct NOM #'s car?

 

[Jack]

Ok, I will pop off the valve covers sometime soon when its not 100 degrees here. I guess the consensus is that it isnt an original block, and I agree. So, how much money do you think it would take to get a 1970 350/350 corvette engine that I could put in there to make it a correct NOM #'s car?

I dunno ... but it'd probably be a bunch ... and ... since the serial number won't be right on pad ... it still won't be numbers matching ... even if you fake the stamped numbers an expert can tell. Other than seeking a possible rebate from seller for possible misrepresentation, I suggest you quit sweating it and proceed with enjoying the car.

 

[Vettehead Mikey]

I suggest you quit sweating it and proceed with enjoying the car.

That's some good advice. Replacing your engine with another NOM is throwing good money after bad.