Changing a few things can help with heat.
I have a MERV, (similar, but not the same) and with taller than stock tires (buggy rear Hawgs on Rebels) I am able to run 2S in parallel for 1 hourish run times without heat issues. I have a ********* 60 ESC and a few other upgrades.
This is what I had when I very rarely walked away broke.
Steel hollow balls (7028x) to reduce slop
3M mushroom tape along battery doors to hold the body on
Aluminum knuckles to reduce slop and add strength (I have HR but recommend GPM or GH)
A BlueBird 390 servo due to the stock being known to fry/strip itself
RPM a arms at all four corners (Front-80692, Rear-80602)
Center differential (7014) upgrade to help handle the power of
2200mah 2S 20C LiPo's ran in parallel for ~1 hour run times
23/50 gearing gets me to ~30mph yet keeps temps in check
Shimmed front and rear bulkheads... *
LINK*
Especially do that last part... extremely cheap preventative procedure.