What would it take?--more effort than it would be worth. I don't think the B20 will mount to the B30 bellhousing (and if it did it would mean fabricating new front mounting points) - or conversely if you are installing an M40/41 or BW35 with the B20 mounted to the front crossmember a new, longer front driveshaft section will need to be made and balanced and if stick shift, clutch cable and shift linkage worked out. All in all, not such a great idea. You're certainly right about it sure to be "sluggish" -- lugging around more weight (164- longer wheelbase) with less torque and a rear axle ratio made for the 6 cylinder.- Dave