I used a 194 small chamber head & it was the best my car ever ran with,mainly because it made a lot more compression 12.0:1

IIRC, the intake valves were 1.88 & the chambers were not touched, I wanted maximum compression.

I did mill the head a lot down to 50 something cc's.

If you were to install it on a stock 250 w/stock camshaft, more likely it will detonate.

If you run small valves you really do not need to unshroud much on the chamber walls. If going w/larger intake valve approx 1.88" you would need to unshroud the chamber & you need to know where to do so. Unshrouding the chamber walls it not just done where the valve is closest to the chamber.

MBHD


12 port SDS EFI