Engine ?

[Mark A.]

Hi, new to the site I`m always reading the posts I just have`nt posted a question on here until now since I came across a motor that I`m not sure about so I thought I would ask here.

Heres the info the block number is 3963512 the date on it is G3070 also on the front of the block is HI-PER an by the oil filter it reads HI-PERF PASS

The heads number is 3994026 the date on them is E1071 they are iron they also say HI-PERF

There is no VIN on the block could this be a over the counter block or some warranty block? It also has 4 bolt mains on it. This would`nt be a LS6 would it? Any ideas?

Thanks Mark

[Ls6 Ragtop]

Mark,
3963512 blocks were used for LS6 applications with the 4-bolt mains as you say this block has.
G 30 70 is too late for production LS6 cars for 70. It's only production line usage would be for a 71 LS6 Corvette. What if anything is stamped on the front pad? 3994026 heads are over the counter square port cast iron open chamber heads with no production line useage.
If the block has been decked and is unreadable, you'll never know what it originally was.
Chris