Tips for HP gain?

Has been thinking of heads but is there any major gain to justify 1600 bucks?
I gave 730 for a pair of Speedmaster heads fully loaded on black Friday sale. Don't know how your ported heads would stack up to them, depends on the porting job. Throw on a 750 DP and tune it. TUNE..... Speed is slow in the 1/8 even for bad traction.