LS5 long block value?

Andy · #1 12-30-2007, 08:04 AM

This is the only forum I thought this question would fit, but if it needs to be moved some place else, then that is alright. My uncle has a complete LS5 longblock from a Chevelle. I am not sure what year LS5 it is but he is fairly certain it is from a 1970 model. It has been sitting on a stand for years and needs to be rebuilt. What would a motor like this be worth? The casting number on the back of the block is 3963512, and it has two bolt mains. It was an engine from a manual trans car I believe. It still had the flywheel on it. I will have to ask what the numbers are on the front pad, but I know that it had a C on the front pad, but I can not remember what the other letters/numbers where. The attached photo is the only picture I have of the complete motor.

666 the legend · #2 12-30-2007, 08:14 AM

...Could be a "427" or a " 454" according to the casting #'s..!!

**rubbinisracing** · #3 12-30-2007, 08:25 AM

The casting date will be very important

**427king** · #4 12-30-2007, 08:50 AM

[ QUOTE ]
but I know that it had a C on the front pad

[/ QUOTE ] sounds like a 70 ls5 with a c code..also if its a 3 digit suffix its 70 or later and a 2 digit would be 1969..I's and L's[not c's] are normally found in 69 corvette and impalas.The c could also be CE

Andy · #5 12-30-2007, 09:06 AM

It is a C followed by two other letters. I'll get the info tomorrow and post it up on the board. Is there any other places I need to have him look on the block other than the front pad?

**Rixls6** · #6 12-30-2007, 02:00 PM

If it's an original LS5 from a 70 Chevelle, then the code should be CRT. Chances are it's out of a car from Atlanta and would have the partial VIN stamped on the front pad also, like: 10Axxxxxx

If it was a Van Nuys built car, then the partial VIN would be down by the oil filter.

**ANDY M** · #7 12-30-2007, 06:53 PM

According to Colvin, the "512" block was the only Chevy block used as both a '69 427 and '70 454, since GM had already made the decision to increase the stroke for the '70. This casting was also made with both 2 bolt and four bolt mains, and used in the big Chevys and 'Vettes in '69, and Chevelles added in '70.

Andy · #8 12-30-2007, 11:44 PM

T0904CRN is what is stamped on the front pad. So it would be Tonowanda Engine Plant, September 4th and according to the big block engine suffix codes on http://www.nastyz28.com/gm-chevy-cod...-suffix-12.php, this is what it came out of.

CRN 1970 Chevelle 454 360hp manual trans LS-5

Andy · #9 12-31-2007, 12:27 AM

I've seen two different hp levels with this engine as well, 360 hp and 390 hp, which is correct?

**Mr70** · #10 12-31-2007, 02:02 AM

Are you sure it's CRN?,I think that's out of a 1970 Monte Carlo with an LS-5/360HP M/T originally.
390HP was for the Corvette & Passenger series & Police/Taxi vehicles.
Are you sure it's not CRT?