HELP Big Time

[truckerboy]

Hi, i am new here, but my truck is not

I have a 89 K1500 Silvarado equipped with a 350 TBI, 700R4, and a stock shift on the fly 4x4. (maybe NP435)

ok, i have a lot of work to do on this truck. The motor is weak (more explaination coming) The heads, (maybe gaskets), are shot. I havent got the truck down here yet to get a good look at it. Also i think the mains and rod berings are shot, hell if it was a ford then it would not run at all. But best of all I have been able to drive it half way home with the aid of 70 gallons of water and 4 gallons of oil, its all goin somewhere, but where is beyond me. It will start, after fighting a while, and drive till it overheats (5-10 miles at 65-70 mph) then i have to stop, wait a while and refill it, then get back on the road. 40 down 43 miles to go.


What i want to know is, Will it be better to rebuild this engine, or buy a crate engine? I dont know that much about all this, but i am woundering, would a 383, 400, 427, or 454 work? which one is the best for hauling a trailer, while haveing the ability to haul ass too? I really want to fix this on my own, but i will need a lot of technical help.

[benoit454]

well if you go with a tbi setup it's gonna be alot of questions and gonna need a computer tune or chip made for it no matter what engine you do. if you do a stock rebuild cam and all on the 350 it might be ok without a tune. if you want power and pulling power do a 454 427 or 383, but it aint gonna be cheap and it will require some questions and work. Also may want to look into the rear end gears, so what it's got in it now. You could get up and go really quick, smoke tires and tow the heck out of anything with a stock motor and the right gears really, I'd get like some 4.10's or so since you got an OD tranny. Then again the trans. can be a weak point for a good motor like a big block or 383. it will at least need work done to it as well.

[truckerboy]

thanks for the reply.

The truck is running 4.11:1 gears (i replaced thoes myself)

what type of work will need to be done to the trans.? Or how hard would it be to change to a strong strait gear trans.?

Just thinkin at this point, but would you be able to secure a chevy bellhousing to a heavy truck trans., such as the old "super 10" or something of the sort?

[BIGphillip79]

I'd say going with a crate motor or having that one rebuilt would be the same money unless you can do a lot of the work yourself. You gotta think parts and machine work. You can get a crate rebuilt 350 at autozone or whatever for like 800 bucks. Get your heads checked out and redone at a machine shop put her together and your good to go. Just don't forget to change or upgrade the bolt ons while you at it. New water pump, hoses, belts, wires, cap and rotor and egr valve. Clean your intake inside and out. A decent t set of headers and exhaust and air filter system can help in the cojones department.Have the radiator cleaned or get a new one. A 350 is fine for all around use. Like Benoit said look into gears. Everyone looks to a cam and all the other engine stuff for power but gears can show all kinds of hidden beef a stock motor has. Bad thing is you got to do front and rear, That'll double the price for gears, but while you at it drop a couple hundred more bucks and get a posi like an eaton or a detroit true trac. Great for towing.

I've got the same truck you have. When I got it it was shot. Bad motor and 2 cracked heads. Had it back on the road for I think about $1500 doing the work myself. Bought and rebuilt a 99 short block and bought and rebuilt some stock heads.

[benoit454]

I don't see why not. by straight trans you mean a stick shift or like a th350 or something? A kit is availible to make a th350 bolt in place of a 4x4 700r4, I got that in my 88. A stick shift could be made to work pretty easy I'd think.

As for stock 700 I'd think rebuild, and performance bands clutches maybe, servos, shift kit, maybe manual lock up kit or something. I'm sure it'll hold up decent to a stock or mild build but some high torque or high Hp motor, you're gonna loose alot of it at the trans if it's not built to match.

I rebuilt my 88's 350 tbi with all new stuff for less then a grand. I didn't need any machine work other then hone(did myself), I put in new cam, lifters, timing set, gaskets, oil pump, belt, plugs, wires, dist., rings, bearings, and fluids. Probably others I forgot, only things I didn't change was the water pump and hoses I think, and that's because they were already new. I also didn't change injectors, but did change fuel filter and O2 sensor. I think I had roughly 300-400 in motor parts and another 200-300 in tune up stuff or maybe closer to 400 with the $110 distributor I had to buy.

[BIGphillip79]

Dude you need a bigger truck. If you don't get too crazy with the motor and towing the 700r4 is fine. Bowtie Overdrives and some other companies offer some heavyduty 700r4 that will work well and bolt right in. If you need more you can get a 350 or 400 and put them in with little trouble but fuel mileage will suffer. 400s were offered in 3/4 and 1 ton models with 350s, 454s and diesels. If thats not enough you need a Peterbuilt.

http://www.bowtieoverdrives.com

[truckerboy]

dude, i dont want it for towing. The most i tow is 7000 lbs on a trailer. I want the bigger trans to have more gears. More gears= better mileage.

And also just to say i did it. I just love it when i got somethin on my truck that no one else has. Also a heavy truck like that will be able to handle a boat load of torque without much work.

[truckerboy]

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I don't see why not. by straight trans you mean a stick shift or like a th350 or something

Yes it is a stick shift. srry about that, i say it as strait geared trans. so i generally just say its either strait or auto.

[ChevLoRay]

You guys have options....when I was starting to drive in '63, the standard transmission on most vehicles was a stick...3 on the tree. It might have overdrive, but that was an option that a lot of vehicles didn't have. If it had an automatic it might be a Powerglide, or a Hydramatic. In '58, Chevy came out with the Turboglide. It was not a very reliable transmission. The Dynaflow was in Buicks. Hydramatics were in Pontiacs, Oldsmobiles and Cadillacs, but had also been installed in Lincolns in the early 50's and in Hudson's, as well as Chevy and GMC trucks in the 54-57 era.

I said that to say this: There are automatic transmissions that are good to have. I like Allison gearboxes. If you could find one that had been behind a Duramax Diesel, it might be worth considering. If you want to stay with a stick-shift, an SM465 is tough, but it's only a 4-gear. You could add an auxillary behind it and add some more gears, if you wanted to split shift it.

But, this is getting way out of hand in my mind. It was just for your thought process.

A good stout automatic would be easier to drive with the loads you want to haul and be easier on the overall vehicle. Plus, if you were in traffic with a load, the manual gearbox could be a pain. Holding it on hills, etc.....from experience.

[truckerboy]

A good stout automatic would be easier to drive with the loads you want to haul and be easier on the overall vehicle. Plus, if you were in traffic with a load, the manual gearbox could be a pain. Holding it on hills, etc.....from experience.[/QUOTE]


Though the autos are good, if I have to replace it, im putting in a strait geared trans. Really, id rather put up with a thousand shifts in town and drifting on hills to get better milage and less torque and horsepower on the drivetrain. Also the strait gear transmissions, at least in my opinion, makes a better trans anyday.

The 700R4 thats in it is a 4 speed, while a strait geared can be 5 or 6. The more gears that the trans has, the lower the sustained engine RPM will be, thus lengthening the service life, and reducing fuel usage.

As for the autos, I could get a Gear Vendor unit, which I dont even know would go into the 4x4 setup easily or even relaibly. This would also lower the overall RPM, but this would be like $2895. Now doing this with a stout rebuild, that puts just the trans at about $6000. I can get a "Super 10" from a 1978 Mack for $400, clutch and drive shafts, plus machine work to make the 4x4 work was quoted at $2450 so thats 10 forward gears for 2850. Even with the Gear Vendors Over/Under drive unit the 700R4 only has 8. and the whole unit of the "Super" is chearer by about $3000, so i could take that and make a good engine, and maybe a 4-6" lift too.

Based on this what do you think i should do?

BTW, $400 is for the complete truck, so i can get the wiring and all, not to mention the working gauges.

[truckerboy]

Not to mention the fact that i can truthfully say "My truck is more custom than yours"

And a transbrake will help under a load.