Transmission

[AllanT]

I have a 89 s10 ext cab truck i just bought from a guy. He says it has a stock 350 in it all i know is it is slow runs 16.4 at 84 mph in a qtr it has a 700 r4 trans in it and was wanderin what would be better that transmission or a turbo 350. and was also wonder about the rearend, what is a good rearend to put in a s10

[wild85]

The 700R4 is good for a daily driver or highway vehicle but, behind a hot small block will need to be really beefed up which costs alot of money. It has a 3.06 first gear ratio which is not good for a truck that already has traction issues. I started with a 700R4 and destroyed it along with the converter. The th-350 is a stronger tranny alot cheaper and uses less horsepower to run than the 700, but has one less gear.

[bratass]

I chose the th350 because it is cheaper and stronger.

[mountmin]

The 700R4 is an excellent tranny to use in the S-10 swap due to it being an overdrive unit. As to strength and durability, most of those issues have been addressed by both GM and the aftermarket. As usual, care must be taken when choosing a starting piece. A 700 that used to fit behind the 229 V-6,(60 degree), just will not work. If you could get it to mate up with the block it does not have the guts to take the V-8 torque. On the other hand, any 700 that started out behind a V-8 and built after 1986, (some sources say 1989), will do the job for you. The trick with the 700 is setting it up correctly. I have witnessed many of these transmissions \"burn up\" simply because the installer did not understand the relationship that has to exist with the engine and transmission through the TV, (throttle valve), cable. It is not just a kickdown cable like on the 350, it controls all facets of the transmission\'s actions, ie. shift points, shift quality, (firmness), and if not properly adjusted will soon cause the 700 to self-destruct. All of this is explained in much detail by an outfit who has done much more homework than myself. They are Bowtie Overdrives. They have an extensive web site that will answer any questions you have regarding using the 700,(bowtieoverdrives.com). They also sell pieces/parts to help in the conversion task. Using info and parts from Bowtie Overdrives I have about 75,000 miles on my 700, (a 1983 model, not even one of the \"good \" ones from 1986 and beyond) behind a healthy 406 sbc in a \'91 Blazer. I get about 19 miles to the gallon in everday driving and can even get 24 if I try really hard on a trip. Before the 700 I had a 350 and it worked really well, also, I just prefer the 700 and it\'s overdrive and gear ratios. Take the time to do it right and I think you will, too.

[350-s-10]

i have a 700R4 in my truck and i have run in the 12\'s with street tires..... with slicks it will easily be in the 11\'s! the only problem that i have is that i have lost two cases due to poor pinion angle..... will be fixed this weekend but i would highly recomend getting a 700 over the 3 speed trannies. get a brand new one from BowTieOverdrives they are cheap and can handle any power you throw at them and have a warrenty! they are worth every penny and are great people to get help from. the money may seem high but when you get into rebuilding one and find out that you could have bought one with a warrenty and brand new for the same or a little more you will be kicking your self! i know i am kicking my self cause they would have fixed my problems before they happened!

[Scotty_S-15]

Tell me about it...... With my TH350 & 3.91 gears & short tires, my poor engine is screaming down the interstate at 3600 RPM to keep up with traffic! A little OD help from a 700R4 would be a big help! Next time, a 700R4 for sure!

............BTW, and addn. tunnel clearance necessary for a 700R4?

[mountmin]

I had no clearance problems except with the dipstick. Simple fix. Bent it to more closely match the curve of the transmission without putting any kinks in it. I had previously bent over the lip where the firewall joins the cab and you might need to do that, but that seems to be pretty common. May not be necessary, it just seems everyone I know likes the extra space.