Originally Posted by fast68plymouth
We refreshed a Koffel built low deck 526(4.375 x 4.375) few years ago that had been run in either a puller or a mud truck(can’t remember which).
It had what I would consider a stage 1 type job(bowls and chambers) on original B1’s.

The heads flowed 392/266@.800 lift

That is about what Koffel's claims their Stage 1 porting flows.