86-87 shortblock vs 84-85

88 CuttyClassic

The Enviromental Hitman
Oct 30, 2001
what are the differences between an 84-85 short block and one from an 86-87 car? pistons? cam? crank? etc....
from what I understand?

The differance is the 86/87 Has a taller deck height, oil return line drilled in the fron of the block, and the lifter valley is casted a little different. Don't think that the hot air shirt blocks are any weaker. I have read, heard and have been told the hot air bolcks are just as good as the 86/87 blocks.
thanks for the replies. i'm trying to do a budget build motor for my 84 hurst and am exploring different options for short blocks. not looking to go faster than 12.50s.... i just want something nice to cruise and that i can rely on not to be broke all the time.
Were there any 109 blocks in 85 that anyone is aware of. I have an 85 with a 109 block and am wondering if it is correct.
Casting number stamped on the block. You can see it by crawling under the car by the transmission. Brad
Casting numbers

If I remember correctly the 84/85 is #848? And the 86/87 is #109 feel free to correct me if I am wrong;)
The only difference is the 86/87 is stronger in the lifter valley. The 84/85 block is a 249 and the 86/87 is a 109 block. Chime in. brad
How is it stronger? Ive never seen one break on any casting in the lifter area on any engine unless the bottom end came apart. Ive seen 20 bolt pan blocks with the part # ending in 140. There are some slight variations in the oiling but thats about it. They are all equally weak especially when stock.