They are gaxr throttle bodies 38mm. It's a xr2i block with crank sensor. People have had good results with bike tbs.

That engine has lightened and balanced bottom end
Arp rod bolts
1300 pistons to raise compression
1640cc ish
stage 3 big valve head with stainless race valves
Kent cvh27 rallym 3500-7500 rpm with double springs and mechanical lifters and adjustable vernier
Then the throttle bodies. Haven't got a clue what it will go like but should be ok.