I'm redoing the 406 in my Camaro and need some serious advice. The engine has already been bored .030", but due to light cylinder wall scoring I need to punch it out .010" more to clean things up. Will a 400 take a .040" overbore? The engine will not be run everyday but will see some drag strip time. I hate to trash the block because it's been decked and relieved and is a 4-bolt.
I plan to buy a new Eagle 3.75" stroke cast steel crank, Eagle 5.7" rods and forged Speed Pro pistons for 5.7" rods. Will I encounter any clearance problems with the 5.7" rods as far as the cam or block? Will these components work together as-delivered?
Also, I spun the engine reliably to 6500 rpm with the stock short rods with ARP bolts and stock cast iron crank. Will the Eagle crank and rods be safe to 6800-7000? I'm asking because I want to go with a more aggressive cam to get more top-end power.
Any advice would be greatly appreciated.
Thanks.

I run 5.7's in a 400 (stock crank). No problems with clearance of cam or block.

.040" is pushing it, but many report it being done succussfully so go with it.

Also, run the steam holes and run a HV water pump, and an ample radiator. With reduced meat between the bores, steam pockets will be more problematic.

Rev-ability is more a function of valve train than bottom end. 6500-7000 shouldn't be problem if you're top end is ready.

What heads are you running? As I've stated, it's hard to get heads that are too big for a 406 (or 408 in your case).

But,..400's,..love 'em! Good luck!

Cooling won't be a problem--I have a 23" 4-core radiator and a Moroso water pump and have drilled the heads for the steam holes. The 406 never got over 190 degrees even in hot weather. The heads are aluminum AFR 210s with the big valvesprings for a roller cam. 6500 was a breeze! I was more worried about the bottom-end flying apart over 6500 because I didn't know how good the Eagle parts are. Thanks!

The Eagle parts are great I rev my 350 to 7200 with no problems. The keys are balancing,good parts and paying attention to details. :)