Novaflyer, If you are creative, you can make a mold out of lite ply and melt the lead, then poor it in the mold and mount it directly to the front if the engine mount. My guess is you are going to need about 10 oz. mounted to the front two bolts of the motor mount. Mold the lead in a U shape and hammer the ends flat then drill a couple of holes for the bolts that correspond to the front two engine mount bolts. replace the front bolts with longer ones, bolt the engine in tight with a set of nuts and then use two more nuts to hold the lead to the bolts. I know it is a pain in the arse but works well and gets the lead where you need it and secure too. alternatively you might be able to screw it to the front of the engine box but you will need more lead, probably 13-14 oz.

One other thing. The stickem that comes on the back of those premade lead sticks has a habit of softening up and letting go when installed inside a cowl, which leads to some interesting flying. (Just ask me how I know! [&o] )

For reference purposes, My GSP Katana took 12 oz. of lead to balance with the Saito 1.80 and stock muffler when the OS 1.60 guys were getting by with 4-6 oz. and they were using the pitts style mufflers from slimline. The Saito's are light but have awesome power, I think you will be happy with it and the lead really won't be noticed other then the fact you know it is there. The only drawback to the 1.80 is fuel consumption. I get an 8 minute flight (3D stuff) outta mine on 14 oz. of Omega 15% I would love to run 30% in it but it's just too thirsty.