Advice needed: Which block?..

[markassbauer]

hey there! i have an 84 shelby charger N/A, i am gonna be running a dual carb intake with 2 downdraft weber 38's. an old nos mechanical cam .528" lift 288/288 duration 72 overlap and 108 centerline, direct connection race head ported, polished and big valved, turbo automaic trans, equal length axles and 11:1 pistons for which ever motor i SHOULd use. so heres my question: do i use my 2.5 tall block? or my 2.5 common block? i have both so budget isnt an issue, and this is gonna be a street car that i will OCCASSIONALLY take to the drag strip, any advice is appreciated and thanks in advance!

[contraption22]

I would stick with a 2.2 and 5 speed if you want to stick with carbs. But if you have your heart set on an automatic, i guess a 2.5 would be better. Go with a common block.

[zin]

Either would work, the tall block would be interesting if you wanted to do a long rod set-up, but the common block is fine for strength... I agree, the 5-speed has a lot going for it, the auto has a few good points too.

If you go the auto route, you'd want to get a higher stall converter, especially with the cam you'll be running, it probably won't start making significant power until 2500-3000.

I also agree with the idea of running the 2.2 in stead of the 2.5, the go-fast goodies you've got will make the engine want to make power at higher than normal revs, and a 2.5 won't like it up there nearly as much as the 2.2 with its shorter stroke. It would probably be even more happy if it were a 2.0L.

Mike

[GLHS60]

Have you seen the high compression 2.5 tall deck long block DetroitTurbo is selling on here??

Thanks
Randy

[DetroitTurbo]

Have you seen the high compression 2.5 tall deck long block DetroitTurbo is selling on here??

Thanks
Randy

Hehe, Mark is my cousin, and I told him if he wanted to use that stuff he could. He just wants to know which would be better. basically everyone has been telling him that the longer stroke from the crank instead of the rods is better for power, so he is most likely going common block.

[GLHS60]

It's been reported that the tall block has thicker cylinder walls. I'm not a fan of the long rod theory but if I wanted to build a high compression 2.5 automatic, yours is a bargain!!

Thanks
Randy

[turbovanman²]

Hard to say, a 2.5 will rev, a street car won't see revs all the time, so I'd go 2.5 common block. A tall deck is a common block plus you'd need custom rods/pistons but if cost isn't an issue, go that route, :p

[DetroitTurbo]

Hard to say, a 2.5 will rev, a street car won't see revs all the time, so I'd go 2.5 common block. A tall deck is a common block plus you'd need custom rods/pistons but if cost isn't an issue, go that route, :p

not quite sure I understand what you are trying to say here. If you mean he will need custom rods and pistons for the tall block, he is doing an n/a motor, so the stock rods are fine, and the pistons I have are already 11-1+ compression.

[turbovanman²]

not quite sure I understand what you are trying to say here. If you mean he will need custom rods and pistons for the tall block, he is doing an n/a motor, so the stock rods are fine, and the pistons I have are already 11-1+ compression.

LOL, for some reason, thought turbo, so in that case, nevermind, :lol: but rememeber, if he want's to use the tall deck, the CB 2.5 stuff won't work except the crank.