NDDan
Guest
You got to be careful for you want to maintain enough draft on floor to keep fairly clean. I have installed 6 and 7" by 12" long chimneys on a few R62 72s to try prevent pooling of heat. Never took any temp readings but am sure engine compartment runs a certain amount cooler. I put stack directly in front of air intake prescreen and is half under hood and half above. Hard to tell it ain't factory and it does vent off a lot of heat. Sounds like you have the grain concave that we have had forever. We have little corn but still prefer the wide wire concave. We just use as many bottom mount filler bars as needed to get good thresh before allowing crop to get threw concave. We only remove everyother wire from old narrow wire concaves if the guy has corn. Other wise we leave as is untill time to replace. We don't install nothing but wide rasp bars but have nothing against narrow over concave and wide on seperator side. We have even used a mixed bag of bars threwout with no problems. We do have alot of very hard to knock out spring wheat which seems to be hardest crop of any I've been around to knock out.