i would get a bisson muffler- i use the pitts style mufflers with the g90 mounted at 9 oclock and the tube a 6 oclock or so. you will want to crimp the outlet tubes of the muffler down a little so they look like an oval horse race track. this adds a little more back pressure and the g90 will run just a bit more consistently at different throttle settings. but i ran my g90s for years without doing this so its not a big thing. anyway the g90 likes the apc 14-6 prop, at least i like the way it flies my warbirds.

i would also recommend usng air baffles to direct the air over the engine piston area mainly. this will reduce the amount of cowl you will need to remove for cooling the g90. anothe thing you might consider is leaving some increased area between the cowl and the fuse behind the head.

not to confuse things but how much will the corsair weigh when its done? if its 10 lb or more then the g90 will be ok but not as strong as i like. the best alternative then is the st 2300, which is a 1.4 cubic inch engine. they are going for very good prices.

one more thing- you didn't ask about retracts but for this plane i would highly recommend you your retracts from sierra. the robarts are not real strong, and for only a few dollars more the sierra retracts are far superior. they come with the oleos included and look very strong. but as i don't have any corsairs you should do some searches here in the warbirds forum and you will see lots of threads about rotating retracts and comments from guys who have struggled with their rotating retracts.

good luck-

ed