Probably not what you want to hear but..if you insist on using the tunnel ram find a good 400 short block it will help the low end a ton.If you can find some old double hump heads in good shape fairly cheap they would work well.They have 64 cc chambers and some had the 2.02 valves. I WOULD not spend much money on them as there are far better after market heads out there for the money it will take to go through a set of dh..but sometimes you can find used ones pretty cheap. Definately get a 400 short block if your gona use a tunnel ram. just my opinion.