[vferrizz]

My '66 has 4:56 gears...not very street friendly. Should I swap out the ring and pinion or am I better off replacing the whole rear end? I am looking to go with either 3:73 or 3:55.

Vince

 

[diesel158]

My '66 has 4:56 gears...not very street friendly. Should I swap out the ring and pinion or am I better off replacing the whole rear end? I am looking to go with either 3:73 or 3:55.

Vince

I think you'd have to replace the carrier.

 

[sschevellefan]

What series carrier do you have? You might have to swap carriers but if you have a 3 series, you can run a 4 series gear with a ring gear spacer. Is this a 10 bolt or 12 bolt?

 

[big gear head]

Need more information about the rear end. Swapping the gears is usually the best thing to do. It requires some special tools and some knowledge of how to set them up properly.

 

[vferrizz]

Folks,

Thanks for the replies. I guess I have to start doing a better job providing enough information. I'll re-post later today.

Hey diesel158, "Leave the gun, take the canoli's"...one of my favorite movie lines.

Vince

 

[vferrizz]

The rear end is a 12 bolt. As for the series carrier..I have no clue. How do I figure that out?

Vince
'66 SS

 

[sschevellefan]

The 3 series gears have a thicker ring gear and the 4 series have a thinner ring gear. Someone who knows the part numbers might be able to tell bt the number. Are they GM gears or aftermarket? I`m pretty sure all GM 4.56 gears were 4 series but some aftermarket companies make them in 3 and 4 series. You would need to know what series you have when you order new gears anyway.

 

[big gear head]

Look at the posi case. There will be a casting number next to the bearing on the end opposite of the ring gear. It will be a EDB30140 for the 3 series and a EDB30174 for the 4 series.

 

[vferrizz]

Thanks for the replies. I'll check it out.

Vince
'66 SS