Merlin is out of a P51, That's the blower on the back of the engine. Carb is lower left corner. box looking thing up top is the intercooler.
Radial (R2800) was used in Hellcats, Bearcats, Tigercats, Invaders, Corsairs, Marauders, Thunderbolts, DC6 & Convair 240's, CH37 Mojave helicopters etc. A26 Invader version in the pic.