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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: dstark on June 28, 2011, 03:41:50 pm

Title: Re-gearing from 4.11 to 3.42
Post by: dstark on June 28, 2011, 03:41:50 pm

I got a quote from a shop here in Dallas on what it would cost to swap my 4.11 gears out of my 14 bolt FF to 3.42. The mechanic asked if it had a "six bolt pinion housing".

Will I have to crack open the pumpkin again to see or is there a way to know without looking before taking it to the shop?

Also, he quoted me $950 to regear if it has the six bolt pinion housing. If not, it would be cheaper. Is this a fair deal?

Thanks

(1976 Chevy C20 350/4BBL/TH350/4.11)

Title: Re: Re-gearing from 4.11 to 3.42
Post by: Irish_Alley on June 28, 2011, 04:29:40 pm

14 bolt ff is easy to gear i think thats too much but i never priced them i have just dont it myself. to tell if its a 6 bolt just look at where the driveshaft bolts to the yoke on the pinion you will see  if the pinion housing is bolted on they are big bolts not some little ones that you can miss
(http://www.pirate4x4.com/tech/billavista/14b_bible/images/Design-2.jpg)

Title: Re: Re-gearing from 4.11 to 3.42
Post by: Captkaos on June 28, 2011, 04:48:55 pm

I would imagine he is wanting to verify that it is a Full float.  The pinion housing bolts to the differential with 6 bolts on them as opposed to a semifloat with doesn't

Title: Re: Re-gearing from 4.11 to 3.42
Post by: Irish_Alley on June 28, 2011, 08:11:41 pm

i think the ff has the 10.5 ring gear and the semi floater has the 9.5. the bolt on pinion to me make it easier to set it all up. like capt said if its a ff its 10.5 sf 9.5 but only the 10.5 has the pinion bolts

Title: Re: Re-gearing from 4.11 to 3.42
Post by: dstark on June 30, 2011, 04:07:54 pm

So I'd be better off getting a rebuilt 700r4 to drop RPM's on the highway at that price, agreed? And with the SBC 350 and 3/4 ton, I would need a shift kit to beef it up some so it won't go out, right?

Title: Re: Re-gearing from 4.11 to 3.42
Post by: zieg85 on June 30, 2011, 06:14:02 pm

As far as final drive goes a beefed up 700R4 will turn less rpms with your 4.11 than re-gearing to 3.42.  Keep in mind you have to make provisions for the TV cable to operate proper shifting which may include or may not include a different carb.

Title: Re: Re-gearing from 4.11 to 3.42
Post by: Irish_Alley on June 30, 2011, 07:23:06 pm

what are you doing with this truck? dd, big tires & kind of race?

Title: Re: Re-gearing from 4.11 to 3.42
Post by: dstark on July 01, 2011, 06:44:29 pm

I'm wanting a good resto-mod driver. Looking for decent mpg, decent power on the low end, and head-turn appeal. Going with the Edelbrock 1406. Just had SB350 rebuilt. Likely going with the 700r4. Getting heavy duty front coils, 1.5" rear spacers, and some nice 32" tires underneath. Needs paint and interior, then we're ready to roll.

Title: Re: Re-gearing from 4.11 to 3.42
Post by: Irish_Alley on July 01, 2011, 08:45:42 pm

with only 32s i would not get 4.10 keep what you have or 3.73 at the highest

Title: Re: Re-gearing from 4.11 to 3.42
Post by: VileZambonie on July 01, 2011, 09:03:01 pm

700R4 is the way to go.