Originally Posted by American Muscle
i was thinking of putting a 142 on my 305. Is it just a bolt on, tune and go sort of deal or do i need to go inside and do some work
A stock low compression ratio short block that is in good condition is fine
for the boost you will be using on the street.
Detonation is avoided by correct tuning. by not getting greddy n boost, on pump gas.
jetting, tming under boost, good 92+ octane pump gas.
7psi boost is plenty and will add +++100hp+++ to a 305.
A blower friendly cam is nice to add.
The Summit SBC hyd's make a great blower cam
Dual pattern wide LSA. eg summit cam #1102 1103 1105
Some of the factory SBC cams make great blower cams EG: 350HO 330hp vortec crate motor cam 212-222 .430 .460 112
EG 327 350hp "151" cam 221-221 .447 -.447 114
EG the 350 LT4 hot cam hyd roller cam 218-228-.525-.525 112
EG the ZZ4 crate motor roller cam 208-221- -471 .510 112 .
Crane cams has many many off the shelf hyd solid and roller cams that are great as blower cams.
a 750carb works great. a few mods and rejetting is needed to dial it in. A spark retard box "BTM" is great.
blowers love improved cylinder head flow just like any motor does.
Port the stock heads to get some flow on.
or port some stock large chamber 350 heads (1.94 valve)
to drop the cr even lower (7.5:1) for high boost on pump gas.
5 to 7psi and 8.5:1cr works real good on the street.
Your 305 will make the power and torque of a 400 to 425cid engine
Its not rocket science and is very cost effective.