Too much trouble? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

3chevys · 08-13-2004, 05:50 PM

I want to trade out my 4.11 gears for 3.40 or 3.73. Its in a 72 2wd 12 bolt rearend. I have never tried this before, can I do it in my garage or am I better off taking it to a shop. Limited mechanical knowledge, but I did do a frame off resto on the truck by my self, except the engine rebuild.

LUV2XCLR8 · 08-13-2004, 06:19 PM

Welcome To The Board From W. Tn.

redz 1970 K5 · 08-13-2004, 07:25 PM

For thoughts sake, have you considered keeping the 4.11's and adding a 700R4 or 5 speed trans?

I think a 4.11 is a little much for daily driving with a TH350/400, but man it would be sweet with an OD transmission!

Now that is aside, sounds like you have good know how, so long as you are patient and don't mind pulling the carrier in/out a few times and take your time you can do it.

It's not rocket science, and most of the guys who do regear in shops have only 1 thing on you- they have done it before. I think you can do it!

3chevys · 08-13-2004, 09:16 PM

any idea what it would cost to put in a 700r4. what i have now is a mildly built up 350 with a 3 speed automatic turbo 350. if i do remove the 4.11 do i have to replace the whole rearend or just the gears themselves. i am assuming just the gears and if so where is the best place to get them.

earl87gta · 08-13-2004, 10:09 PM

Depends on the price of the 700r4 it is 3in longer then the 350 I think so drive shaft may need to be made shorter and you will need a break switch with 2 leads so that you can use it for the converter lock up or just buy the wiring kit its only $75 then universal shift lincage is like $40 or use a floor shifter. trans lines you can bend a new set for less then $20 other then that the price of the trans Ive seen them go from 100 to 2500 depending on used rebuilt or built up. I just gave a hole 88 comarro away with one in it that you could have had just to get the car out of the yard.

Mike C · 08-15-2004, 09:58 AM

A built TH200 is the way to go. Same overall length as a TH350 with same yoke. Just put crossmember in TH400 position. Has a better first gear for the 4.11 IMO, and more overdrive. Figure $1000 for a built trans and new converter. Figure $450 or so to do a gear swap. If you want the gears to last, you are best off paying someone who has experience with setup to handle it. Dropping from 4.11 to 3.73 is only about an 8% drop, not worth the expense compared to the 30% OD afforded by the trans swap. Plus it has a lower combined first gear ratio for better acceleration.

3chevys · 08-15-2004, 10:59 AM

sounds like the trans swap is the thing to do. any idea what i could get for selling the th350 once its out?

Jimmy72custom · 08-15-2004, 02:41 PM

I sold my TH350 for $200.00 when I went to a SM465. I sold it locally and advertised it as being able to test drive.

08-13-2004, 05:50 PM	#1
3chevys Junior Member Join Date: Jul 2004 Location: Bend, Oregon Posts: 37	Too much trouble? I want to trade out my 4.11 gears for 3.40 or 3.73. Its in a 72 2wd 12 bolt rearend. I have never tried this before, can I do it in my garage or am I better off taking it to a shop. Limited mechanical knowledge, but I did do a frame off resto on the truck by my self, except the engine rebuild.

08-13-2004, 06:19 PM	#2
LUV2XCLR8 The LuvShack Garage Join Date: Jan 2004 Location: Maple Grove, TN (West Side) Posts: 30,482	Welcome To The Board From W. Tn. __________________ Owner/Op: "TN Classic Transport Carriers" The Toy: "Square Vette" 72 Hybrid Blazer Toy Barn: "LuvShack" 40 x 60 x 20 Shop Tow Piggy:"Maddy" 88 Silverado 3500 Hauler: "Feathers" 14 Aluma 8218T

08-13-2004, 10:09 PM	#5
earl87gta Senior Member Join Date: Dec 2003 Location: Kingsport TN Posts: 4,641	Depends on the price of the 700r4 it is 3in longer then the 350 I think so drive shaft may need to be made shorter and you will need a break switch with 2 leads so that you can use it for the converter lock up or just buy the wiring kit its only $75 then universal shift lincage is like $40 or use a floor shifter. trans lines you can bend a new set for less then $20 other then that the price of the trans Ive seen them go from 100 to 2500 depending on used rebuilt or built up. I just gave a hole 88 comarro away with one in it that you could have had just to get the car out of the yard. __________________ Earl 68 2500 4x4 GMC Burb

08-15-2004, 09:58 AM	#6
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,723	A built TH200 is the way to go. Same overall length as a TH350 with same yoke. Just put crossmember in TH400 position. Has a better first gear for the 4.11 IMO, and more overdrive. Figure $1000 for a built trans and new converter. Figure $450 or so to do a gear swap. If you want the gears to last, you are best off paying someone who has experience with setup to handle it. Dropping from 4.11 to 3.73 is only about an 8% drop, not worth the expense compared to the 30% OD afforded by the trans swap. Plus it has a lower combined first gear ratio for better acceleration. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

08-13-2004, 07:25 PM	#3
redz 1970 K5 OBS guy Join Date: Jun 2004 Location: SoCal Posts: 1,060	For thoughts sake, have you considered keeping the 4.11's and adding a 700R4 or 5 speed trans? I think a 4.11 is a little much for daily driving with a TH350/400, but man it would be sweet with an OD transmission! Now that is aside, sounds like you have good know how, so long as you are patient and don't mind pulling the carrier in/out a few times and take your time you can do it. It's not rocket science, and most of the guys who do regear in shops have only 1 thing on you- they have done it before. I think you can do it!

08-13-2004, 09:16 PM	#4
3chevys Junior Member Join Date: Jul 2004 Location: Bend, Oregon Posts: 37	any idea what it would cost to put in a 700r4. what i have now is a mildly built up 350 with a 3 speed automatic turbo 350. if i do remove the 4.11 do i have to replace the whole rearend or just the gears themselves. i am assuming just the gears and if so where is the best place to get them.

08-15-2004, 10:59 AM	#7
3chevys Junior Member Join Date: Jul 2004 Location: Bend, Oregon Posts: 37	sounds like the trans swap is the thing to do. any idea what i could get for selling the th350 once its out?

08-15-2004, 02:41 PM	#8
Jimmy72custom Registered User Join Date: Apr 2004 Location: Willits Ca Posts: 261	I sold my TH350 for $200.00 when I went to a SM465. I sold it locally and advertised it as being able to test drive.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.