Gear Ratio Question..

[WILMASBOYL78]

I was just reading one of the threads that mentioned the 4.10 axle ratio in 70 for solid lifter Camaros. Prior to 1970 could you get a performance ratio with a non-solid lifter engine?? eg; L34 Chevelle with a 4.10 or steeper rear or were there restrictions??

wilma

[SS69chevelle]

My info is specific to 1969 chevelles but I looked at my 1969 Chevelle Protect o Plate list and found two, one with a 325 hp manual engine and one with a 350 HP engine and they had hydraulic lifters. I would think you could have ordered it as an option on any Chevelle if you were willing to pay for it. According to the reference image I have (Bow Ties and Tail Fins), for 1969 Chevelle options, there were 6250 of the 4.10 option for 1969 chevelles. The 4.10 gear required posi-traction and cost was $56.90 and included a heavy duty radiator, same as the 3.73 gears as listed in the Chevrolet Motor Vehicle Price Schedule. take care, Andy

[Mr70]

I think 1970 saw a new ratio allowance on certain engines,do to thier increasing Horsepower and possible warranty concerns too.
1969 Chevelle,Elcamino w/<span style="text-decoration: underline">L-35</span> 325HP engine,w/o Air Conditioning &amp; equipped w/3spd. &amp; 4spd. trans. could get the 3:73 posi or 4:10 posi for extra cost.Neither ratio was possible with a TH400 trans.
Only the 3:73 was possible for an extra cost,(No 4:10),on those when A/C equipped,but only when equipped with the 2.52:1 low 4spd.

Chevelles equipped w/<span style="text-decoration: underline">L-34</span> 350HP engine w/o A/C,and ANY transmission,could get the 3:73 posi or 4:10 posi for an additional cost.
Only the 3:73 was possible for an extra cost,(No 4:10),on those when A/C equipped.

<span style="text-decoration: underline">L-78</span> 375HP engine Chevelle &amp; Elco could get an extra cost 3:73 posi or 4:10 posi with the TH400 or when any M/T ratio was ordered.A/C was not possible on this engine.


I have a list for all the other 1969 vehicles,including Corvair,but didn't know if you wanted those or just the Chevelle.

[WILMASBOYL78]

What about the steeper gears like 4.56 or 4.88...would these have been restricted to the solid lifter cars in 68-69??

I was aware of the 1970 limitations...too many CE motors in the past [img]<<GRAEMLIN_URL>>/rolleyes.gif[/img]

Did the same rules apply to other GM divisions?? I think there were some pretty steep ratios available on the Pontiac, Olds and Buick performance cars...and none of those were solid lifter.

wilma

[Don_Lightfoot]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: WILMASBOYL78</div><div class="ubbcode-body">Prior to 1970 could you get a performance ratio with a non-solid lifter engine????

wilma </div></div>

I had a 4.10/M20 in a L48 Camaro I restored back in the mid 90's. Confirmed by POP. It would make sense the same would be available for a L48 69 Chevelle.

[Mr70]

An L-48 '69 Camaro could have gotten the 3:73 posi or 4:10 posi for an extra cost when it came with either a 3spd. or 4spd. only.
But the L-48 equipped '69 Chevelle could not,and was only allowed the 3:08,3:36 or 3:55 posi.as an upgrade depending on the trans ordered.

[Don_Lightfoot]

Good stuff Rick.