396/425 feedback
Melting Slicks
Joined: Oct 2001
Posts: 2,740
Likes: 4
From: Marblehead MA
I haven't had mine that long so I can not really comment on its' durability. I do remember the Chevy BB's were notorious for sucking in valves, but I am sure that today's technology solved that problem. The other problem that I seem to recall was the cam lobes going flat, and that some of the cams would "walk", again I think this problem was fixed years ago. 
As for its' capability, mine revs like there is no tomorrow. I can easily pull it to the 6500 red line, and I am sure some internal mods were done, but I wouldn't know until I pull it apart, and that's not going to happen at the start of driving season.....
As for its' capability, mine revs like there is no tomorrow. I can easily pull it to the 6500 red line, and I am sure some internal mods were done, but I wouldn't know until I pull it apart, and that's not going to happen at the start of driving season.....
Instructor
Joined: Feb 2006
Posts: 140
Likes: 1
As delivered they can have oiling issues if you really buzz them. Removing the windage tray and making sure the oil pressure isn't too high usually resolves this. However autocrossing them can still be dodgy. And the rod bolts ain't the best. But if you're not abusing the thing it will be OK anyway.
Burning Brakes
Joined: Mar 2002
Posts: 962
Likes: 13
From: Camarillo California
Originally Posted by gpizz
I've owned two 396's over the years, they are the best big blocks in a corvette. Unlike the 427's *( I've owned 6 ) they do not overheat, and they rev alot higher than the 427's.
I've never heard this before. I can understand why a 396 (with its smaller bore) might be less prone to overheating, but why would it rev higher than a 427? Both engines shared the same stroke and valvetrain. Are you saying it's due to lighter piston weight?
Drifting
Joined: Nov 2003
Posts: 1,645
Likes: 65
I owned both 396/375's and 427/550's and both were great motors. The 396's were close to stock, so I didn't rev much past 6,000 the 427's were L88 cloans + and were reved to 7,500. They were the most fun I ever had coming out of the hole and smoking anything that was next to me. Then contining to pull away with all that HP at the top end.
By the way I broke a lot a of drive trains in Nova's and mid "A Bodies" before getting it right.
I do not remember which year, but when GM went with the higher spring rate double spring all spring problems went away. If I remember correctly it was very early in the 396 life and the problem was very apparent on the low HP versions not used in the Vette. I do not remember the high HP 427 ever having the problem, only problem was the 2 bolt bottom end letting go if the revs got high.
By the way I broke a lot a of drive trains in Nova's and mid "A Bodies" before getting it right.
I do not remember which year, but when GM went with the higher spring rate double spring all spring problems went away. If I remember correctly it was very early in the 396 life and the problem was very apparent on the low HP versions not used in the Vette. I do not remember the high HP 427 ever having the problem, only problem was the 2 bolt bottom end letting go if the revs got high.
Last edited by tentuna; Apr 1, 2006 at 07:38 AM.
Instructor
Joined: May 2005
Posts: 216
Likes: 0
From: Southeast PA
Originally Posted by gpizz
I've owned two 396's over the years... Unlike the 427's *( I've owned 6 ) they do not overheat, and they rev alot higher than the 427's.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
The 1965 396/425 L78 is the same identical engine as used in the 396/375 Camaros starting in 1967 through 1969. With the proper OEM cooling systems there have never been overheating issues in any of the BB`s in all configurations from mild OEM to wild OEM including {ZL1, L88, and the LS7`s} 