I'd much rather put HP on the firewall to make the plane balance. I will not use lead.

Why would you put a ST90 or a TH 75 on the firewall and then add 6 or 7oz of lead? Get a heavier engine.

How is that going to effect the way the plane flies? Same weight. Weather you put on a light engine and lead, or put on a heavier engine and no lead. Both combinations will weigh the same. But a heavier engine will at least pull it's own weight. Asking a lighter engine to pull it's own weight AND lead is not the best thing to do. Not to me, anyways.

It doesn't have to be a Saito engine. I know they are expensive. You can get a ST2300 for $150. GMS 120 for $130.

Put on a bigger engine to balance it and then use a 3-blade prop for cool factor. It is a warbird. An underpowered warbird will not be much fun, so I'd buy the big motor to balance it and then slap a 3-blade or 4-blade prop on it. High Speed Scrafing Runs [sm=thumbup.gif]