[bullittprod]

G'day guys how ya doin ?
what would be involved in puting my 76 bonneville engine in a pre unit 500 650 frame like this ?

i like the single downtube !!!

 

[tombat]

At the minimum you would have to use specially made motor mount plates, other than that I don't know specifically as I've never attempted to put a unit engine in a pre unit swing arm frame.... better idea (in my opinion) would be to put a pre unit in it as God (and Meriden) intended. Good luck!
tombat

 

[chopperjunkie73]

if u can cut and weld anything is possible

 

[Loffer]

sell it and get a unit frame.

 

[hillbillyhell]

sell it and get a unit frame.

What he said. A 63-70 unit 650 frame is A: a bolt in deal, and B: a better frame than the preunit.

 

[BackPorchChoppers]

Not really all that hard man I'm in the process of doing the same thing now because like you I like the single down tube frame. All you really have to do is reconfigure the center down tube and make a mount to accept the motor mounts. Kinda like this.