I have a 396 (402) now - with some issues and I have a line on complete 427 from a 67 corvette - with internals and heads to rebuild to replace it.

Maybe a dumb question, but can you tell the difference between the two once it is all buttoned up and in the car? I believe I can use my water pump, pulleys, balancer, valve covers.

Just wondering if there is a subtle difference that you would notice between the two from the outside. From what I remember the 427 is just a 396 bored and the heads are designed a little different inside.

Thanks

99 out of 100 couldn't tell the difference.

Normally it would be hard to tell the diff bewteen 396 vs 427 with both being 67 motors.

Most 396/427 motors used same heads depending on output,lrg oval port vs lH/Perf sqr port.

But again,your avg person would not know the difference unless you could see the pad on rt front of motor and knew the engines codes for 396 vs 427 for 67 and you cant see casting id on rear of block with motor in car either.

Scott

Perhaps in power only as they share the same physical dimensions externally. Casting number and code on block pad as mentioned above are the tip but number stamps are available.

If it is a 67 427 Vette motor, put it on eBay!
Build a killer 496 with the sale proceeds!

The cranks have the same stroke 3.76.
The 396 crank is lighter having 3/4" wide 3rd counterweight.
The 427 cranks look identical except the 3rd counterweight is 7/8" thick, heavier crank due to heavier pistons for the larger bore.
The flywheel flanges are identical....
internally balanced
COLVIN, "Chevy by the Numbers 65-69"

Balancer, flywheel, flexplate, short water pump, intakes, heads, all swap between 396 and 427. Most of the 67 BBCs looked the same, 396 or 427...differences would be in the small details to fit a specific application. Vette engines should have the rear of the driver valve cover with a slant for example. Some engine block casting numbers are found on the side of the block by the starter.....

Thanks for the answers !!!!