WyoFlyer, I fought that fight a few years ago. Then it seemed the 6v wiper motors were all 12v motors (regardless of what the ads said) which gave less than stellar performance on 6v. I didn't know about the possibility of a 6 to 12 volt booster (I now run one for the 12v radio). My solution that I'm still happy with is I sent the old vacuum motor to WiperMan in New York and for a bit over a $100 I got a original motor that works fine and is true to the truck. Well the truth is it works fine within the limits of vacuum motor. If I ever get around to installing a vacuum tank I think it'd work fine with no excuses.

Good Luck,
RonR


RonR


1951 3600 with Clark flatbed, T5, 4.10 rear
1970 340 Duster
1990 5.0 V8 Miata (1990 Mustang Gt Drivetrain)
1964 CJ5