Looking to build a Honda 250r need help

[ron250r]

I'm looking to build a Honda 250r trike. I need help with interchangeable parts I need help with the engine wanted to know if bottom ends are changeable from the early models 81-84 with 85-86 would a 85 top end work on a early model bottom end was there any major changes with the bottom ends any help would be greatly appreciated I'm new to the trikes but ive been building lt500r and 450r quads right now and I'm looking to start building a Honda atc250r

[Mr350x]

The 85-86 250R were water cooled where as the earlier ones were air cooled.. I know it wouldnt directly bolt on, I don't think you could mod it to fit either but that's just my thoughts, Never heard of it anyways..

[RIDE-RED 250r]

You cannot mix and match air cooled and water cooler 250r top and bottom ends.