g-man
SILVER Star
Stock the H55F had 4.11:1 diff gears. Not sure a H42 with stock 3.70:1 would have that much higher RPM on the highway.
It WILL lower your rpms and if you don't like the sound of your engine at 3000 rpms while trying to maintain 65 mph, a 5 speed can put you at 65-68 mph at a comfortable 2500 rpms and you can get to 70 mph and still be well below 3000 rpms. This with 31" tires on 15 inch wheels and 3.70 rear gearing. Why is 3000 rpms a big deal? I know the engine can run like that all day ...i just don't like hearing it. Sounds like she's cranked out of the frame loud.