If your looking for a bit more power and thinking engine swaps the MA61 chassis is a much better option for doing those sort of conversions than the RA60.
I wouldn't fiddle around with the 21RC and 22R engines as they are old and are bound to be a big money pit and take as long as JMCFs project decade.
So i say just keep the ol celica running well for as long as you need it, buy an MA61 and drop an engine in that and replace bushes and refresh the brakes and suspension while your at it.
Sam
Bookmarks