700r4 upgrades

[83K5guy]

what kind of upgrades would yall recommend me doing to my 700r4 4x4 trans for my blazer, im looing into get a vortec 350 block and maybe doing an aftermarket efi kit unless i can get my hands on a harness and computer for the vortec. im looking around 300-350hp/tq. what would yall suggest

 

[crazy4offroad]

I would suggest dont use the 700r4 lol. I know, it's not what you wanted to hear. Maybe HRPC can chime in and give some upgrade tips for the internals.

 

[oneluckypops]

what kind of upgrades would yall recommend me doing to my 700r4 4x4 trans for my blazer, im looing into get a vortec 350 block and maybe doing an aftermarket efi kit unless i can get my hands on a harness and computer for the vortec. im looking around 300-350hp/tq. what would yall suggest

Honestly thats kind of an open ended question. Some upgrades are not needed depending on what you use the vehichle for.

We know what your looking for in HP/TQ, which isnt excessive so an Extreme Transmission is not manditory.
How about your gears? What gears do you have and what gears are you wanting to run?
What size Tires are you wanting?
What kind of budget?

If your wanting to go with a vortec with OEM harness and injection why not go ahead and run the 4L60E instead of the 700R4?

I could help you out with a harness, I have already started deleting un needed wiring from the harness also, Computers are really pretty easy to get off of e-bay usually around 50-100 bux for the VCM. Harness's can go for as little as $50.00 Plus shipping.

If your interested in me modifying my harness or another harness for you send me a PM.

 

[83K5guy]

Looking at no bigger than 33" tires, gears now I believe are 3.08 thought about keeping them as 700r4/4l60 hAve a pretty low 1st gear but may jump to 3.73's.
I may have to send you a pm, I'm trying to do this on the cheap but not cut corners and waste time and money to half ass things. Its not something I like to do. I'm still waiting to hear back from my friend about his 350 vortec, I'll let you know pops on the harness

 

[HotRodPC]

I'll add more later to the this and help you out, but right from the get go, If you are going to run 3.08, I'd just go with a Th350. You won't need overdrive running 3.08 with 33 or 35in tires. If you are paying for a gear change, it costs no more to go 4.10/4.11 than it does 3.73. With that tire size, I'd run 4.10/4.11 and then use the 700r4/4L60-E. The lower gear you can get, will take that much more strain off the transmission, and 700r4'4L60-E can use all the help they can get.

Do keep in mind, with all the upgrades I'll suggest, you'll have some coin tied up in this transmission. One reason I haven't built my 700r4 yet, if I figure it'll cost me close to $500 in the parts alone and that's not even including hardened shafts yet. But I can build a Th350 for about $125 in parts and that included a stock build and a shift kit. And the Th350 is likely to hold up to 300hp no problem.

 

[oneluckypops]

Looking at no bigger than 33" tires, gears now I believe are 3.08 thought about keeping them as 700r4/4l60 hAve a pretty low 1st gear but may jump to 3.73's.
I may have to send you a pm, I'm trying to do this on the cheap but not cut corners and waste time and money to half ass things. Its not something I like to do. I'm still waiting to hear back from my friend about his 350 vortec, I'll let you know pops on the harness

700R4's first gear ratio is 3.06:1, If I was you I would DEFINETLY plan on a gear change No offense but 3.08's suck ass. If you want to go with 33" tires I would strongly Reccomend going to a 4.10 ratio, 3.73's would be a big help but I dont reccomend running any bigger then a 31" tire with 3.73's.

If your wanting to do it on the cheap, and you are just getting a motor with out the 4l60E Transmission then we can delete the Transmission Harness to where you essentially will have a stand alone Injection Harness for the 5.7 Vortec. The painless harness is from what I have heard a really good harness but it is Pricey, If you choose to go with a stock harness, that will save you a **** load of cash. What kind of deal are you gonna get on this vortec motor? and what all is it going to have with it?

 

[HotRodPC]

I'd also like to point out, as many will tell you, the 700r4/4L60-E has a deep first gear of 3.06 as Pops said, which is good to get you going from a light, but also keep in mind, the downside to that is the big wide ratio gap between 1st and 2nd gear. If you by chance are hot rodding or towing a load, you will certainly notice that wide gap from 1st to 2nd. Carrying a load, you'll think you should have stayed in first gear longer, but really, NO you shouldn't have, that's just one of the downside charachteristics of having the nicer 1st gear. This is one reason the 5 and 6 speed automatics are so good. Get low first gear, but yet not a wide ratio gap either. You can have your cake and eat it too.

 

[83K5guy]

Okay if I did decide on goin th350 I know I'll need a tcase adapter right, also would I need a different x-member or can the 700r4 be moved and modified easy, what about my driveshaft legth or will the adapter take up the length. Would I be fIne running the th350 with 3.08 and 33" tires. I'm looking for this to be a daily drive so I'd like to have good fuel mileage as I can, kind of the reason for trying to keep the 700r4

 

[Christian Nelson]

Kinda confused on the gear ratio thing.. I had a truck with 4.56 ratio, and I had to put 38's on it before it would stop opening the secondaries to cruise on the freeway with traffic. That truck would barely get 6mpg! With my 3.73's on my half ton with 36's on it, I could get between 12 and 14 mpg, and never felt underpowered, or like I was lugging, and I could keep up with traffic on the highway no problem without feeling like my engine would blow from the revving.. Why do you guys want such low gearing?

I like to have my v8's at around 2k @65mph. I've noticed a lot of reccomending of 4.10's and 4.56 where I never thought it was an issue with 3.73's on any of my trucks..

You all have more steep hills or something??

 

[bucket]

I'll add more later to the this and help you out, but right from the get go, If you are going to run 3.08, I'd just go with a Th350. You won't need overdrive running 3.08 with 33 or 35in tires. If you are paying for a gear change, it costs no more to go 4.10/4.11 than it does 3.73. With that tire size, I'd run 4.10/4.11 and then use the 700r4/4L60-E. The lower gear you can get, will take that much more strain off the transmission, and 700r4'4L60-E can use all the help they can get.

X2

Kinda confused on the gear ratio thing.. I had a truck with 4.56 ratio, and I had to put 38's on it before it would stop opening the secondaries to cruise on the freeway with traffic. That truck would barely get 6mpg! With my 3.73's on my half ton with 36's on it, I could get between 12 and 14 mpg, and never felt underpowered, or like I was lugging, and I could keep up with traffic on the highway no problem without feeling like my engine would blow from the revving.. Why do you guys want such low gearing?

I like to have my v8's at around 2k @65mph. I've noticed a lot of reccomending of 4.10's and 4.56 where I never thought it was an issue with 3.73's on any of my trucks..

You all have more steep hills or something??

It makes a big difference with overdrive. I'm guessing you had a th350 or th400?

 

[HotRodPC]

Okay if I did decide on goin th350 I know I'll need a tcase adapter right, also would I need a different x-member or can the 700r4 be moved and modified easy, what about my driveshaft legth or will the adapter take up the length. Would I be fIne running the th350 with 3.08 and 33" tires. I'm looking for this to be a daily drive so I'd like to have good fuel mileage as I can, kind of the reason for trying to keep the 700r4

Actually NO, you will NOT need a Tcase adapter. Th350 and 700r4 will use the same adapter. They can also use the same crossmember and driveshaft too. The only hitch to using the same crossmember location so you don't have to lengthen your driveshaft, it to get an adpater for the rear of the your Th350 and have it built with the correct Th350 output shaft that matches the adapter. That is what I just did. Took a 700r4 out and installed a Th350 and I am running 3.73 gear with 31x10.50x15 tires.

 

[83K5guy]

Well what specs on upgrades needed to be done to the 700r4

 

[HotRodPC]

Well what specs on upgrades needed to be done to the 700r4

Just as a start and if for a stock rebuild, here are some things I'd go with.

Beast Sunshell (or Smart Shell) Both by Sonnax
Corvette 1-2 Servo
Sonnax release springs for 3-4 clutch pack.
Z pak or Alto Commercial 3-4 Clutch pack
.500 Pump Boost Valve
Transgo Jr Shift Kit or Transgo 2 Kit
Go with a 10 Vane Rotor and Vanes if its not already. Could be 7 or 13, but 10 is best. 7 is not enough, 13 puts to much strain on the pump rotor and will break the rotor.

If turning over 6,000 rpm, I'd also sleeve the input drum, there is a kit to do this.

If towing a light trailer and still intending to use Overdrive while towing with thie trailer, I'd go with a SuperHold 3-4 Servo.

 

[83K5guy]

Thanks

 

[Christian Nelson]

X2



It makes a big difference with overdrive. I'm guessing you had a th350 or th400?

On that truck, I had the TH350.. But, from what I am reading the advice is that even with the TH350, they are advising 4.10 gear ratios at anything bigger than 33" tires.

Hence my question about hills because I never thought 3.73 was bad with my 36" buckshots at all. But then, I am in midwest, not mountainy roads, and we cruise around 70 on the freeway, and I want the RPM's as low as possible without lugging.

I try to set my engines up with stump pulling low end torque too, no open headers, radical cams, etc. I don't want an engine that doesn't come to life til I get to 5,000 rpm.. I want one that makes power from 1,000 to 2500, because that is where I like to keep my rpm's in most cases.