[Richard/SIA]

So now the ten bolt peg-leg rear is leaking on my El Camino.

With the radical cam 350 and 2400 stall TH400 the factory 3.31 or 3.35 gears are a tad tall.
Would a 3.54 be enough lower to actually help?

Do not want to go too low as this is a long distance car not a dragster.

The 3.54's would come to me in a Jag IRS - Dana 44, with LSD, but that's another topic.

 

[Verle]

As a round number, running 50 MPH you would lose about 3 MPH at the same RPM.

 

[Richard/SIA]

So, not really significant below a hundred. :yes:

Also not going to hurt from a standstill even if it doesn't do very much.

 

[O'Man]

So, not really significant below a hundred. :yes:

Also not going to hurt from a standstill even if it doesn't do very much.

Seriously doubt you could tell which is which if you could run back to back road tests with the two ratios in the car. Differences of .2n are just not seat of the pants discernible.

 

[BillsCamino]

You could adjust those minor effective net gear ratio changes by simply running a shorter tire.

 

[Richard/SIA]

Running a 26.6" dia. x 14" rim now.
May have to go to a 15" rim when I change the rear, tire also gets 1.00" taller.

 

[zookpr]

Running a 26.6" dia. x 14" rim now.
May have to go to a 15" rim when I change the rear, tire also gets 1.00" taller.

The above is NOT true. By switching to a 15" rim does not make the tire 1" taller. The tire diameter depends on the profile tire that you buy.