91 crewcab...got a couple questions

[Ta2edjr]

So I'm going to look at a 91 crew cab 2wd dually tomorrow...few things I'm wondering....the truck has a tbi 350 with 700r4 does this sound correct for a one ton truck...I figured it would have a th400 or 4 spd and more than likely a bbc under the hood. But those arnt my main concern..can anyone tell me what size brake lines this truck would have on it? Has a small leak and plan on fixing it. The truck isn't that far from me but I don't have any one with a truck big enough to haul a 1 ton crew cab long bed lol. Hopefully I can get a couple compression fittings a piece of line and bring this thing home tomorrow.

[WyattTX]

You can probaly buy brake lines pre bent. I can't be sure about the transmission. Though I believe 700r4s were mostly intended for 1/2 tons, but I've heard of heavier trucks having them anyway,though people who really uses these trucks change them out to the heavier duty th400.

[dragn91]

Dont use a compression fitting replace the rotted line and do it right. Those compression coupler fittings are not designed for brake system pressures. You can always buy a couple lines and if theres any extra length loop it. And if it has overdrive it may have a 4l80e and if it does you lucked out i think they were only available in the late model one tons. If it has a 700r it was probably swapped in but i could be wrong

[Ta2edjr]

Well after talking to the owner it's the rubber brake line on the front so I'll just change it out no big deal there....and I'm assuming it's got a 4l80 in it I do believe that's what comes in it factory I'd say the owner just dosnt know enough and that they assume it's a 700 because it has overdrive...only time will tell I'm going to look at the truck tomorrow.

[bilfman]

91 did have the 4l80e.

[WyattTX]

I doubt someone would put a 700r4 in it, that wouldn't make any sense. Either it has a factory 700r4, or some other overdrive transmission. The only way to tell is to crawl under the truck and look. The shape of the oil pan, and number of bolts will tell you.

[WyattTX]

One thing I forgot to say is if you look up the VIN, you'll know what transmission it left the plant with.

[SCOTI]

Originally Posted by WyattTX

I doubt someone would put a 700r4 in it, that wouldn't make any sense. Either it has a factory 700r4, or some other overdrive transmission. The only way to tell is to crawl under the truck and look. The shape of the oil pan, and number of bolts will tell you.

Yes & no. Someone would put a 700r4 in one to save a few bucks & still have OD. 4l80e's are more expensive & 700r4's are more obtainable.

[Ta2edjr]

Well the verdict is in....it does have the 4l80. Trans..truck fired right up and sounded good. Didn't pull the trigger on it though..it needs more than just brake lines to be driven home 4 of the 6 tires are shot and I just don't have the time to mess with it right now. I leave for out of town work in 2 days..also the small block that was in it was tbi but it didn't have center bolt valve covers so I'm guessing. It had a engine swap at one point in time....I could be wrong. But for a 91 model truck I figured it would have the newer style heads

[foamypirate]

Originally Posted by Ta2edjr

Well the verdict is in....it does have the 4l80. Trans..truck fired right up and sounded good. Didn't pull the trigger on it though..it needs more than just brake lines to be driven home 4 of the 6 tires are shot and I just don't have the time to mess with it right now. I leave for out of town work in 2 days..also the small block that was in it was tbi but it didn't have center bolt valve covers so I'm guessing. It had a engine swap at one point in time....I could be wrong. But for a 91 model truck I figured it would have the newer style heads

My 88' crewcab was the same way, TBI 350, perimeter bolt heads. I looked up the casting number, and it showed up as an 88-91 truck 350. Maybe the 3/4 and 1 tons used different heads?

[Ta2edjr]

You could be correct. I just assumed it would have the earlier vortec style center bolt heads. Lol