i have the stock motorcraft carb not to sure what carb it is but im pretty sure its a motorcraft cause it looks completly stock. ive had friends tell me that there is a way to change its performence by turning a screw on the crab its self. if any one has any clue on where this supposed screw is or have any tips on how i can getsopme better perforce with out having to buy a new crab let me know thanks
If it's the standard old motorcraft 2v. the only tuning screws are the idle rpm and the air/fuel mixture idle screws.
You notice and performce gain by adjusting either of these.
But if the truck is running ruff you may be able to smooth out the adle w/ these.
Hope this helps.
You can really wake up the M series motors with a pre 73 351c timming set. They had a 13degree retard from the factory for emmisions(on the M motors) fixing this is good for at least 30hp! Ad an edelbrock performer intake and 600cfm edelbrock carb with the timming set and really wake it up!