does a b20A5 out of a 91 prelude si. bolt directly to a b21A1 transmission and ecu also in a 91 prelude si.

 

i'll refer to b21a1 as 91si....and b20a5 as 89si
you need to get the flywheel and clutch assembly from the 91si

you have obd1.....

the 89si has IAB (intake air bypass) butterfly valves....and the 91si does not......

you will also need to get entire intake manifold from 91si.....if you plan on using stock 91si ecu.....

if you are going to go for a chipped ecu.....doesn't matter.....the settings can be adjusted to whatever....

you got more questions.....I got tons of answers......I did this swap a year ago.......now I got h22 in my 91

 

thanks cause my b21a1 has a small crack in the block and the head is fried but the transmission, intake manifold and everything else in the car is fine. cause i found b20a5 for real cheap and i didn't know if the ecu and tranny would match up to my b21a1.