Big Block ID assistance..

[dutch]

I have access to a Big Block that has a casting number of 3999289 on the back top - a stamping of T0123TSK on the pad along with what appears to be T5S507311 partial VIN and GM 10P on the bellhousing back under the flywheel along with a 74-67 CONV cast there as well..
Anyone care to try and decode this for me - I'm thinking 454 - early '70's possibly a truck engine - but I'm not sure..  It had 336781 heads on it but not sure if they are original nor am I sure if the block is 2 or 4 bolt mains yet..
Thanks for any help - Randy!
 

[cook_dw]

TSK = 1977 454 truck block

[bertfam]

Going by the VIN (T5S507311), it's a 454/215 (LS4) from a 1975 Truck assembled at the St Louis, MO plant.

Ed

[cook_dw]

Whoops.  That’s my fault.  TSK is 75 454. I looked at the list again and it’s both 75 & 77.  Sorry.  Good eye Ed.

[dutch]

Thanks guys - When I get back to it I will take off the pan to see if its 2 or 4 bolt - but being a truck likelihood is it could  more probably be a 4 assuming more trucks than cars probably got the extra fasteners!
Any idea what the vin count started off at in that year run.. being January 1st would assume it would likely be 500000 making it the 7311th produced or is that thinking correct or ?

What is the likelihood that the 336781 heads that are with it
are correct for it? Don't know what the date code on them is and I'm not close to take a look at this point..?

[dutch]

Thanks guys - When I get back to it I will take off the pan to see if its 2 or 4 bolt - but being a truck likelihood is it could  more probably be a 4 assuming more trucks than cars probably got the extra fasteners!
Any idea what the vin count started off at in that year run.. being January 1st would assume it would likely be 500000 making it the 7311th produced or is that thinking correct or ?

What is the likelihood that the 336781 heads that are with it would be correct or original to that style or number of block and are 781's a decent performance head in any way for a performance package?
I don't know what the date code on them is and I'm not close to take a look at this point..?

[bertfam]

The 336781 heads are probably original, and they're good for bench pressing or boat anchors, but horribly inadequate for high performance. Unless you plan to drive 55MPH all day, dump them in favor for some aftermarket heads. As for truck production, I have no idea what the VIN's start with, but 500001 sounds reasonable.

Ed

[ko-lek-tor]

Sorry Ed, don’t know where you heard that? all info I have says those heads are the hot ticket for a spirited track or street car. A pair of cores go for about $300 with worked over higher. Said to be a good flowing head.

[bertfam]

Sorry, I was going by "hear-say" when I wrote that. I've no personal experience with them so if you say they're good, I'll have to concede.

Ed

[dutch]

Thanks for all of the help and time..  Much appreciated! 
Randy