Visit The Dirt Forum for More Information

Author Topic:   5.0 or 302
Big Bird
Dirt Full Roller

Total posts: 27
posted November 08, 2002 07:44 PM
whith block would make a better 347 need all and any help tyhanks

Dirt Forum Champ
Total posts: 620
posted November 08, 2002 08:26 PM
either is up to the task. most of the 3.40" stroker cranks will work in either block. as far as the block goes, i think the main difference is the rear main seal.

however, a mexican 302 block is beefier and heavier.

Dirt Maniac

Total posts: 135
posted November 09, 2002 07:49 AM
My time with the 5 liter boys with big doses of nitrous showed that the Mexican blocks were best, followed by 302/289 2 piece seal(the earlier the better), and then the roller blocks. At some point in time(my memeory fails me), Ford took a lot of weight out of the 302, but when the horsepower started creeping up in the mid 80's, their durability testing showed weakness, which they addressed by rebeefing the block. Bottom line: '78 and earlier, 87 and later. Keep in mind these were 10 second drag/street race cars, and the conditions were somewhat extreme, but I never saw an early block split right down the middle, and the early ones also showed way less main cap movement.

Dirt Full Roller

Total posts: 35
posted November 09, 2002 08:53 AM
depending on your class rules ford also makes a 302 "b" block for about 800 new it is beefier than the standard roller block but lighter than the big "r" block

Dirt Full Roller

Total posts: 61
posted November 11, 2002 10:59 AM
my experience is the later 5.0 blocks will withstand about 450 hp reliably. any more and they tend to crack around the main cap webbing. The earlier blocks seem to be a little beefier, but if you want to make a lot of power without the hassle of cracking a block (or a leaking rear main), Ford motorsports sells a sportsman 5.0 block that is similar to the old mexican blocks but is set up to use factory roller stuff and has a lot more material around the main cap webbing area. They are supposed to take 600hp without a problem. I think retail on them is about 900$$

Back to the Archives