Forum Discussion
PatJ
Aug 28, 2020Explorer II
jrbelk wrote:
I've got 98 coachman class C 454 with 4:11 rears. I want to improve mileage by going to 3:23 gears. Will this work? Thanks
I think you would probably end up with worse mileage in the end if you did that, in additional to terrible performance and short transmission life. Don't do it, especially if you have overdrive. I'd switch to 4.56 if anything.
Improve the mileage with a good solid tune up new filters and ignition wear items. I admit I don't know a lot about 98 454 in the van chassis, is it TBI? If so make sure you have good coolant temp sensors and it is showing it is warmed up correctly as per the computer. With TBI everything is based on coolant temp. Make sure you have 195 tstat. Make sure no vac leaks. Make sure fuel pressure is to spec. If you need to do anything with fuel or ignition make sure to use OEM GM parts not cheap ebay stuff.
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