ive got a 1972 Scamp with a decently built 318 and its got a 7 and 1/4 rear end. does anybody know what the gear ratio is?

 

More than likely 2.76 ratio. To make sure, you have 3 options.

1) Look for a ratio tag on the rear cover bolt,
2) Jack it up and do the turn and count. If it's open you only have to jack up one wheel. Put the car in neutral, and spin the tire one time while counting the number of times the driveshaft rotates. If it's open, double the number you get from the driveshaft rotations and that is the ratio (approximately). 1.3 turns for an open rear should be 2.76.
3) Pull the cover off the rear and find the ratio stamping on the ring gear.

The 7 1/4 I had in my 318 powered 73 Dart sport was 2.76 until i blew it up. Do yourself a favor and start hunting for an 8 3/4. 7 1/4'S are VERY weak and don't hold up well behind a V8's

 

ive been looking for one for a while and i want to put 3.73's in it. thanks a lot

 

You would need to have it narrowed, but I have a complete drum to drum 8 3/4 w/ 2.76's from a 70 Polara that I'd like to sell. $125. You pick it up. I live in the northeast corner of MD. If you or anyone else is interested, let me know.