Holy crap!

[crackedback]

3.4 stroke according to the builder

and 13 blocks as backups when the stock block craps the main saddles

going in a 68 Dart

 

[RustyRatRod]

3.4 stroke according to the builder

and 13 blocks as backups when the stock block craps the main saddles

going in a 68 Dart

If that's the case, they offset ground a stock 383 crank, probably. Either that OR the builder just rounded off the 3.375 to 3.4. The latter is probably the case, I bet.

 

[polyjohn]

Truly wonderful from a stock 400 block!

My Moparmate had a Koffel 547ci with a 71 400 block.
Made over 900hp and another 250hp of NOS on top.
If you look at my avatar you can see the car it was in.

8.30 at 180 back in the early 90's...
Pump gas as well, Koffel is a GOD!!!

 

[dvw]

3.40" stroke would be a .030" over 400 4.375" bore. I helped Scott K in the 80's when they ran a similar combo in Comp Eliminator. As I remember back then they made 850-875? They ran B/D
Doug