[sedanblue33]

Is a 3.55:1 an 8 inch rear end? Or does it have to be smooth to be an 8 inch? Thanks
Im confused

[RagHead]

3.55:1 is the gear ratio that is in the rear end. It could be in a 8 inch, 9 inch or even a 7.5 rear end.

[sedanblue33]

oh, okay thanks

[dlofc]

3.55 is the gearing in the rear end. In a 74 there was 2 rearends sizes available and that was a 6.25 inch rearend and an 8 inch. Poke your head under the back side of the car if you can see bolts then you have a 6.25 (like mine) if no bolts are able to be seen then it is an 8 inch which is the preferable.

[sedanblue33]

If it is a 6.75 inch i will have to change the rearend if i put a 351w in, won't i?

[dlofc]

sorry about the 6.25. I was trying to watch the kids and type. But in short for regular driving it would probably last for a lil, but for any kind of racing or hard driving I would upgrade defintely. On one final note, you said this is a 74, have you did the research about what is neccessary to swap a V8 into the 74. If not it is worth searching the II forums for it, it is just more involved then the 75 and up because the 74 is very unique. Only mustang ever designed NOT to have a V8 so it will need a alittle more attention the normal but hey it is good. But if you live near springfield MO there is a junkyard in Aurora MO (45 min from springfield) he has 6 II's in it and 3 of them have 8inch and he wants 125 you pull. But good luck

[sedanblue33]

That's cool, thanks i actually went up to Missouri last weekend. (Went canoeing) Yeah i have been researching, i have went through every single Mustang II forum since 2002. Thanks for the info , i might just go up to Missouri.