BB questions
Thread Starter
Drifting
Joined: Jun 2006
Posts: 1,912
Likes: 12
From: Schaumburg (Chicago) Illinois
BB questions
I need opinions on the following:
Would I realistically be able to tell the difference in accelertion between a 327/350, 350/350and a 427/390? (want a big block but not sure if it is worth the extra money)
Do 427/390 run hot or need regular tuning maintenance?
does 427/390 run on regular unleaded?
What is the difference between a 3 and 4 speed besides an extra gear to shift?
Would I realistically be able to tell the difference in accelertion between a 327/350, 350/350and a 427/390? (want a big block but not sure if it is worth the extra money)
Do 427/390 run hot or need regular tuning maintenance?
does 427/390 run on regular unleaded?
What is the difference between a 3 and 4 speed besides an extra gear to shift?
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by AWilson
I need opinions on the following:
Would I realistically be able to tell the difference in accelertion between a 327/350, 350/350and a 427/390? (want a big block but not sure if it is worth the extra money)
Do 427/390 run hot or need regular tuning maintenance?
does 427/390 run on regular unleaded?
What is the difference between a 3 and 4 speed besides an extra gear to shift?
Would I realistically be able to tell the difference in accelertion between a 327/350, 350/350and a 427/390? (want a big block but not sure if it is worth the extra money)
Do 427/390 run hot or need regular tuning maintenance?
does 427/390 run on regular unleaded?
What is the difference between a 3 and 4 speed besides an extra gear to shift?
depends
no
gear spacing
My .02, hop up a small block before you swap to a BB.
Race Director
Joined: Jan 2000
Posts: 13,011
Likes: 2,249
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
The 427/390 is the "mildest" of the three. The first two are 11.0 compression motors with fairly decent cams. The 427 is a 10.25 motor with a very mild cam etc etc. It will be the smoothest of the group while running similar as far as power wise.
The small block versions have forged pistons, the 427 you are looking at is a cast piston motor. It's just basically a station wagon motor that is big enough to run well. But with a little work they can run 11's pretty easily!!
Big blocks with a 4 speed are always the coolest one to get!!
JIM
The small block versions have forged pistons, the 427 you are looking at is a cast piston motor. It's just basically a station wagon motor that is big enough to run well. But with a little work they can run 11's pretty easily!!
Big blocks with a 4 speed are always the coolest one to get!!
JIM
CF Community Team
Joined: Oct 2004
Posts: 19,341
Likes: 5,232
From: Cape Cod, Mass.
2025 C6 of the Year Finalist - Unmodified
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2021 C8 of the Year Finalist Unmodified
2020 Corvette of the Year Finalist (performance mods)
2019 C1 of Year Winner (performance mods)
2017 Corvette of the Year Finalist
2016 C2 of Year
2015 C3 of Year Finalist
My 68 427/390 and my 65 327/350 are pretty close in acceleration; Probably because the 427 has an automatic and a 3:08 rear and the 327 has a 4 speed and 3:36's. The 427 makes a little more low end torque. The small block runs a little bit cooler. Both require premium fuel. I use 93 Octane. They are both high compression engines. The big block is 10.25 to 1 and the 350 horse small block is 11:1 compression.
Le Mans Master
Joined: Mar 2002
Posts: 6,217
Likes: 1
From: End of the Ike IL
Cruise-In V Veteran
Cruise-In VI Veteran
Does a 427/390 run hot or need regular tuning maintenance? Not mine. I have a high flow 180* thermostat with a clean stock radiator, a working clutch fan, and all of the seals to pull air through. It's timed and tuned right, and stays between 180* to 210*.
Does 427/390 run on regular unleaded? I use premium because she likes it. And she deserves the best.
Does 427/390 run on regular unleaded? I use premium because she likes it. And she deserves the best.
