View Full Version : 406 small block
jdb1981
09-16-2013, 03:02 PM
i have a 406 small bloch it is a gm block from the 70 s how much power can it handle thanks
762.86hp at 6184rpm......Just screwing with ya. Way to many variables to answer that. Can be built to handle a bucket of hp though. How much money you got is the only thing holding you back.
RonOwensRacing
09-16-2013, 06:18 PM
The GM blocks crack real easy if you put a lot of compression in them .
the 400 blocks not good for a lot of power.
Well i have broke a lot of them through the years anyway.
zipper06
09-16-2013, 06:32 PM
They can probably handle around 600 HP. i have 2 of them a 4 bolt and a 2 bolt that's in my car now on alcohol. I don't know how much HP it has but it runs 6.50's in my 3250lb Malibu with a toilet bowl, got 200/300 passes on it.
One thing you must absolutly do is put 1/8" pipe plugs in the water holes to keep it from breaking /cracking between the head bolts i also plug the steam holes.you should also run head studs not bolts. I've ran them for 25 yrs. and the biggest problem i have had was not preparing the block deck properly. With that said i've also cracked cylinders on blocks that the casting bores was was not centered, so it's a good idea to have the block exrayed to determine the wall thickness and have the bores shifted to made the cylinder wall's more equal.
JMO
Zip.
bjuice
09-17-2013, 08:30 PM
They can probably handle around 600 HP. i have 2 of them a 4 bolt and a 2 bolt that's in my car now on alcohol. I don't know how much HP it has but it runs 6.50's in my 3250lb Malibu with a toilet bowl, got 200/300 passes on it.
One thing you must absolutly do is put 1/8" pipe plugs in the water holes to keep it from breaking /cracking between the head bolts i also plug the steam holes.you should also run head studs not bolts. I've ran them for 25 yrs. and the biggest problem i have had was not preparing the block deck properly. With that said i've also cracked cylinders on blocks that the casting bores was was not centered, so it's a good idea to have the block exrayed to determine the wall thickness and have the bores shifted to made the cylinder wall's more equal.
JMO
Zip.
X2