when i first did my engine conversion, i noticed this, a huge flat spot below 1800 rpm.
as in NO power at all, go to take off and the engine sounds like its going to die, and the car would crawl at a sails pace untill it hit 1800 rpm then the power would come back instantly, kinda anyoing in the wet as it would wheel spin, and had to back off the accelerator, after fitting the streetfighter II manifold, the problem disapeared, it has now comeback, and is only present when the engine is cold. When when the engine is hot, its not as bad but i can definatly still feel it.
any help greatly appreciated.
edit: it only happens under load, so when it occurs, i hit the clutch rev it to over 2000rpm and then let clutch out slowly as to keep it over the RPM, this will be the only way to get moving

odd one brent, what have you checked so far? Check plug and lead condition, check distributor and cap if possible.

nothing that i can visually see, just kinda odd that when i swapped out the manifold, it fixed the problem, but 10months later its back again

yeah, perhaps it is something that would have been taken off when the manifold was swapped that fixed it temporarily but maybe has come back again? Something might be loose that could cause power loss like a sensor or wiring or something. Maybe the MAF? Have you cleaned it recently?

Nope, but i didnt touch the MAF, would a vac leak cause this problem?

quite possibly, have you still got the original pipe on there?

which original pipe?
oh and it only happens under load