I have the complete Rcm manifold setup fitted to by classic but have read a few posts on here mentioning Harvey's trick uppipe, what's the difference between the two and is it worth trying to find a Harvey spec one ? Also is there much difference in the power output? Cheers all!

 

I can't tell you the difference between the two but I believe it's more about throttle response than power output.
Give Alyn at AS Performance a ring as they stock the Harvey trick up pipe.

 

AS Performance sell Harvey uppipes.

Ossett beat me to it

 

And me, go for the Harvey one, I did.