Honestly man k is overrated. I’ve had a fa5 and currently have a rsx. K’s have a lot of issues, transmissions are junk. Maybe the engine will hold 400hp but it won’t hold any longer than a gsr would. Speedfactory is putting out record breaking cars with b series. I’d say go h for sure. A common issue with those is the auto timing belt tensioner but some aftermarket company’s make manual tensioner conversions for them.
