1991 6.2 or 1999 6.5 Block Advice needed

[welpro222]

Ok guys, I need advice. Which motor is better for rebuilding?

1991 6.2 660 block

or

1999 6.5 506 block

Both are GM and the 6.5 was made in November of 1999 so it should be the revised block.

I will be using my 6.2 heads for it and my goal is durability, no turbo. I think with the 6.5 since it has the 10mm outer main cap bolts, I will not have to buy the DSG Stud Girdle.

 

[emr]

U answered your self, the 6.2 block is worthless...

 

[rnd-motorsports]

For what it sounds like you want then you answered your own question! do not beat on it to much and will live awhile thats the killer of these they are not race engines! but will live long happy service life if treated like a diesel!

 

[southdave]

Wait a min... Do some research.. I suggest going to the diesel page site and look up the best casting number and what they suggest . The 92 & 93 block for a 6.2 are considered by some a superior block than any 6.5.

 

[rnd-motorsports]

Well bye what I get from the diesel page the 6.2 or earlier pre 506 block 6.5 would be the better choice the early 506 blocks were the first attempt for gm at oil squirter's and they were pron to cracking that being said I would stand clear of the 506 and 99 was the start of the 506 block!