??? Questions ??? '72 Ls5

[NEokcTERROR]

I know there are a lot of guys in the know on this forum, so I have decided to ask of couple of questions.

I still have a '72 "CSR" code short block some of you may remember I posted for sale a while back. I have a couple of questions about it some of you may be able to answer.

(1) I have owned LS5 engines out of many chevelles in the past, and they have all been 2-bolt main enignes. This one is a 4-bolt main. Is that a difference between LS5 Corvettes and the other versions used in the other car lines?

(2) The others I have owned (not out of Corvettes like this one) were cast crank enignes. This engine has a steel crank. Is that another Corvette LS5 difference?

Any help to satisfy my curiousity?

 

[Tom73]

1. I thought all LS5's were two bolt mains. Could some one have added 4-bolt mains at some point in the blocks life?

2. Believe that the automatic cars used a cast crank while the manuals used a steel crank. At least that is what was done on the 73 LS4s. The CSR code is for a manual trans.

tom...

 

[NEokcTERROR]

Saga continues

I thought about that. My background is drag race cars, and I have had billet caps and such installed on many big blocks. This block and caps show no signs of machine work other than factory.
I even found the guy (sorta) who is still the registered owner to the matching VIN of the stamp code but I can't get a hold of him, and he is in the same state as me. I called a person with the same last name in the same town, and she said she always gets calls from bill collectors looking for this guy. JUST MY LUCK!

 

[JohnZ]

The 9289 blocks used in '72-'74 Corvette 454 LS-5 applications were all 2-bolt mains, and they all used the 7416 forged steel crank.

 

[NEokcTERROR]

By that you mean I have something odd, or I have something never produced that had to have been modified? I don't have the casting number here right now. I can get it tomorrow. It is at my shop.

 

[JohnZ]

Sounds like it has been modified; the only Corvette 454 that ever had 4-bolt mains was the '71 LS-6, which used the "512' block.

 

[fc3]

Do you want to sell the block? Fred.

 

[NEokcTERROR]

Do you want to sell the block? Fred.

Yes I do. I just wanted to get all the facts first. The block and crank are both standard. It has 3/8 rod bolt rods in it which I understand to be correct. It doesn't have the correct pistons in it as the last person to run it put flat tops in it for a pickup truck application. I have 15 years of history on it. A friend of mine bought it from a guy who would rather have a 350 in his truck instead, so my friend traded him. I was there when they traded, and just thought that was a good deal. When they pulled it out I noticed the big oil fitting above the oil filter, and thought to myself Hmmm the deal just got a little better. My friend stored the short block in a school bus for over ten years before I traded him a set DART 345 heads for the short block and some other parts.

 

[NEokcTERROR]

Casting number 3999289
Casting date c 27 72
Complete stamp code: TO413CSR
Vin stamping: 12S519628

Now another question. If this block has been modified for 4-bolt main caps then why does it have the big oil fitting above the oil filter?

 

[JohnZ]

That block only had 2-bolt mains in any Corvette application, but it was also built as a 4-bolt block for several truck applications up through 1978; might have been substituted for a 2-bolt block at Tonawanda by mistake or due to a material shortage and built as a Corvette "CSR" engine from a 4-bolt-machined block. All 9628 blocks had the raised boss for the fitting, and those machined originally for 4-bolt usage had the hole drilled and a plug installed.