Converting from 4 Spd to Auto. Questions? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Erl · 02-09-2005, 02:47 PM

Interested in the pros and cons of different automatic transmissions and transfer cases for my 68 3/4 4x4. I will purchase them as a unit to make things easier. Would the easiest swap be a T350 trans and trans case asm from a 70-72 1/2 ton. Then the front drive shaft is the same and the trans case shifter and linkage will bolt in. Plus no electronics, only vacuum and a kick down. Not so easy to find and no overdrive. How about a 73-86 series T350 or T400 with a NP205. Will the original front drive shaft still work? Any clearance problems, other than moving the cross member? Are electronics required? Or a 700R4 with a NP208. The overdrive would be great, but how hard is it to control. Just looking for some input before starting to procure the parts.

smokekiki · 02-09-2005, 06:05 PM

I would think the best of both worlds be a 700r4/205 combo.You would need a 205 that has the adapter for a 350th.You would need to put a new output shaft in the 700 from advanced adapters.

784X4GUY · 02-09-2005, 06:13 PM

Quote:

Originally Posted by smokekiki

I would think the best of both worlds be a 700r4/205 combo.You would need a 205 that has the adapter for a 350th.You would need to put a new output shaft in the 700 from advanced adapters.

I would love to have that setup on my 78, that would be sweet...Later..Mike

1976Scottsdale · 02-12-2005, 09:01 AM

For simplicity, a TH350/np205 or 203 is the best. Where I live, both combos are readily available at any salvage yard. I prefer TH350's, but I have never used a 700r4. I have seen all three trannies at their best and worst though, but the th350 has stood up the best for me. Especially since my engine has enough torque to crack the mounting ears off of a transmission when you hammer it(that was a bad day). The th350 combos are easy because as you said, you need only vaccum and kickdown oh yeah, you need to hook up the trans cooling lines too. no big deal.

02-09-2005, 02:47 PM	#1
Erl Registered User Join Date: Mar 2002 Location: Dallas, TX Posts: 555	Converting from 4 Spd to Auto. Questions? Interested in the pros and cons of different automatic transmissions and transfer cases for my 68 3/4 4x4. I will purchase them as a unit to make things easier. Would the easiest swap be a T350 trans and trans case asm from a 70-72 1/2 ton. Then the front drive shaft is the same and the trans case shifter and linkage will bolt in. Plus no electronics, only vacuum and a kick down. Not so easy to find and no overdrive. How about a 73-86 series T350 or T400 with a NP205. Will the original front drive shaft still work? Any clearance problems, other than moving the cross member? Are electronics required? Or a 700R4 with a NP208. The overdrive would be great, but how hard is it to control. Just looking for some input before starting to procure the parts. __________________ 1968 GMC 305 V6 3/4 4x4 Stepside 06 Corvette Daily Driver Dallas TX

02-09-2005, 06:05 PM	#2
smokekiki Mike Join Date: Jan 2003 Location: west chester pa Posts: 2,473	I would think the best of both worlds be a 700r4/205 combo.You would need a 205 that has the adapter for a 350th.You would need to put a new output shaft in the 700 from advanced adapters. __________________ 70'c/10, 71 suburban4x4 402bb, 72suburban 4/6 drop, 72k/5 4x4 blazer 4" lift 35 tires

02-12-2005, 09:01 AM	#4
1976Scottsdale Registered User Join Date: Aug 2004 Posts: 76	For simplicity, a TH350/np205 or 203 is the best. Where I live, both combos are readily available at any salvage yard. I prefer TH350's, but I have never used a 700r4. I have seen all three trannies at their best and worst though, but the th350 has stood up the best for me. Especially since my engine has enough torque to crack the mounting ears off of a transmission when you hammer it(that was a bad day). The th350 combos are easy because as you said, you need only vaccum and kickdown oh yeah, you need to hook up the trans cooling lines too. no big deal.



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