67 rearend with 6 bolt replacement - The 1947 - Present Chevrolet & GMC Truck Message Board Network

badass67 · 04-12-2004, 06:29 PM

The time has come to do the final upgrade
to my 67 stepside. The stock rearend has to go. It has the 6 bolt wheels. Does anyone know what is the best replacement rear end for my application?I would like to keep the 6 bolt wheels. I spent too much money on the wheels and tires. Any advice? It feels like I am stuck on second gear when I drive on the freeway. I have a ZZ4 engine with the 350
transmission. Ideas please!!!!!!!!!!

jmanz69 · 04-12-2004, 06:41 PM

Your problem isn't the rear end it's the gears inside. The stock chevy 12 bolt rear is very strong, I would keep it and get a new set of gears. You probably have 3.73 or 4.10. Get a set of 3.42 or 3.08 replacement gears and have them installed. If you get a different rear, you will have to modify the crap out of it if you have coil springs in the back. If you have leafs, you will still have to remount the spring perches. I know Randy's Ring and Pinion sells new gears for our rear ends at a decent price, then have them installed locally and you are done.

blazerholic · 04-12-2004, 06:42 PM

Any special reason you want to replace the whole rearend? You could re-gear it cheaper I would think. My old 68 (now my bro's) had a 4.11 in it and we switched to a 3.73. Made quite a difference in highway cruising rpm's. He's running a 31" tire which also mellows the ratio a bit. Might even try 3.07 if you spend alot of time on the highway and have low-profile tires. Keep in mind that it will take away some of your low end grunt though.

blazerholic · 04-12-2004, 06:43 PM

ya beat me by a minute jmanz!

badass67 · 04-12-2004, 08:08 PM

I don't really want to replace the rear end,
I just want a better , smoother ride. What about doing the gears plus posi? is posi good for anything in a truck?

jmanz69 · 04-12-2004, 08:41 PM

Posi is good for launching from a stoplight and towing. If you aren't having traction problems then you don't need it. It puts the same amount of torque to both wheels instead of only one wheel spinning. If you like doing burnouts, then you want posi. If you have the coil springs in the rear, you are getting the smoothest ride GM made in a truck. They are the best ride quality, but not as well suited for towing. The Chevy's all came with coil springs and the GMC's came with leafs. The coil spring rears are better for racing and getting good traction. They don't have wjeel hop like the leaf spring rear ends can.

What are the specifics on your truck now? Is it lowered, low profile tires, big rims? You said you have a crate engine, but what about the rest of it. Have any pics? We love pics. If you can't post them, email them to me and I will. jman2619@comcast.net

04-12-2004, 06:29 PM	#1
badass67 Registered User Join Date: Nov 2001 Location: oakland,CA, USA Posts: 32	67 rearend with 6 bolt replacement The time has come to do the final upgrade to my 67 stepside. The stock rearend has to go. It has the 6 bolt wheels. Does anyone know what is the best replacement rear end for my application?I would like to keep the 6 bolt wheels. I spent too much money on the wheels and tires. Any advice? It feels like I am stuck on second gear when I drive on the freeway. I have a ZZ4 engine with the 350 transmission. Ideas please!!!!!!!!!!

04-12-2004, 06:42 PM	#3
blazerholic I am a Gov't Mule Join Date: Aug 2003 Location: Latonia,Ky Posts: 276	Any special reason you want to replace the whole rearend? You could re-gear it cheaper I would think. My old 68 (now my bro's) had a 4.11 in it and we switched to a 3.73. Made quite a difference in highway cruising rpm's. He's running a 31" tire which also mellows the ratio a bit. Might even try 3.07 if you spend alot of time on the highway and have low-profile tires. Keep in mind that it will take away some of your low end grunt though. __________________ ...to die in the saddle must be my destiny, to ride this rockin' horse I must be crazy...

04-12-2004, 06:43 PM	#4
blazerholic I am a Gov't Mule Join Date: Aug 2003 Location: Latonia,Ky Posts: 276	ya beat me by a minute jmanz! __________________ ...to die in the saddle must be my destiny, to ride this rockin' horse I must be crazy...

04-12-2004, 06:41 PM	#2
jmanz69 Careful, they attack... Join Date: Aug 2001 Location: Waterford, MI, USA Posts: 1,107	Your problem isn't the rear end it's the gears inside. The stock chevy 12 bolt rear is very strong, I would keep it and get a new set of gears. You probably have 3.73 or 4.10. Get a set of 3.42 or 3.08 replacement gears and have them installed. If you get a different rear, you will have to modify the crap out of it if you have coil springs in the back. If you have leafs, you will still have to remount the spring perches. I know Randy's Ring and Pinion sells new gears for our rear ends at a decent price, then have them installed locally and you are done.

04-12-2004, 08:08 PM	#5
badass67 Registered User Join Date: Nov 2001 Location: oakland,CA, USA Posts: 32	I don't really want to replace the rear end, I just want a better , smoother ride. What about doing the gears plus posi? is posi good for anything in a truck?

04-12-2004, 08:41 PM	#6
jmanz69 Careful, they attack... Join Date: Aug 2001 Location: Waterford, MI, USA Posts: 1,107	Posi is good for launching from a stoplight and towing. If you aren't having traction problems then you don't need it. It puts the same amount of torque to both wheels instead of only one wheel spinning. If you like doing burnouts, then you want posi. If you have the coil springs in the rear, you are getting the smoothest ride GM made in a truck. They are the best ride quality, but not as well suited for towing. The Chevy's all came with coil springs and the GMC's came with leafs. The coil spring rears are better for racing and getting good traction. They don't have wjeel hop like the leaf spring rear ends can. What are the specifics on your truck now? Is it lowered, low profile tires, big rims? You said you have a crate engine, but what about the rest of it. Have any pics? We love pics. If you can't post them, email them to me and I will. jman2619@comcast.net



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