Will an H22 V-tech head bolt directly on to an H23A1 bottom end? If not, what mods are necessary??

 

look in the "Prelude" section.. right at the top there is a FAQ (Frequently asked Questions). You'll find a lot of info on the H23VTEC swap.

So, to answer you question.. Yes, it does bolt on.. but there are many things you have to take into consideration, like what pistons to use.. you have a lot of reading to do, son.