If i knew what i know niw going back 4 months ago i woulda ripped out both coolers buy a u cooler under tunnel and call it a day , re route cooling lines
I found the 7 tooth drivers to be a good mod. when I installed the 1.75" X 136" on my son's Indy Lite. The reduction in the final drive ratio was very well received by the little 340.
I originally wanted to use the introvert drivers on my install to save cost but I ended up going with the combos instead as I wasn't sure whether I'd have slipping / ratcheting issues.