which rear could this be?

[454HO]

Found an ad for a complete '78 Chevy truck rear end that supposedly has 3.55 gears. I've looked at the aftermarket gear makers and none of them have 3.55 for 10-bolt, 12-bolt or 14-bolt Chevy truck rear end housings. Was 3.55 a factory gear? What would be the most common housing it is in? What is the likelyhood it would have a posi carrier?

[Captkaos]

3.55 wasn't a factory gear ratio, if that is what you are asking about. On a 12bolt it is 3.42 and down and above 3.42 for the split. I have no idea what the 3.55 would fit, but I would assume it is has a spacer it would be for the 3.42 down and if not it would be 3.42 up.

[Jonboy]

If they really are 3.55 gears, it is probably a Ford rearend.

[454HO]

Well I sent the guy an email and tried calling the phone number posted in the ad. No response yet.

I did some more research and found that a 3.55 gear is common for both a 8.2" 10-bolt and a car 12-bolt. If this turns out to be a car 12-bolt, I'm definately snagging it. And yes, this is a common ratio for Ford 8.8" and Mopar 8.75" too.