Tower and GMS build a .75 or .76 in their .61 case, but if you really want power, OS & Magnum build .91s in the same .61 case. All of the .61-.91 engines, except the K&B, weight about the same.

You're not going to tell me the Tower .75 can run with a .91, are you.

As I said in my column a few months back, why would anyone buy a .61 when there are .75s and .91s available in the same crankcase-same weight, loads more power.