Originally Posted by phil_focus
oh, i thought the black top had a better bottom end aswell. thought it was stronger aswell as better length con rods an better sized bores which makes it more responsive to tuning but dont take my word for it as i aint researched it and the info i have is second, third or maybe even fourth hand.
still, cant be a bad combination and atleast the standard conversion is cheap as chips
it only gets expensive when doin charging or throttle bodies as need aftermarket managment aswell
conrods are longer and pistons are shorter so the length is the same overall.
they are interchangeable between black top and silvertop as bore size is the same but the blacktop has slightly dished pistons so compression would be tits up.
the black top is 130bhp and silvertop is 137bhp.
silvertop is a direct swap.
black top needs more work as it has different water pump arangement but it does have better head with solid tappets for higher revving.