I recently bought a 77 K20 4x4 with 178,000 miles and probably the factory engine and tranny. It has a Corporate 14 rear and HD Dana 44 up front. It is gutless! What could I do to get better power? How can I milk this engine as long as possible? Should I rebuild the 350 or move up to a 454? Is a rebuilt 350 enough power to haul heavy loads? Where can I get a good deal on these engines online? It has a 4-speed tranny with granny low gear, what transmission is this? How do I determine what transfer case is on there? Thanks for the help!

That would have an SM 465 trans in it. It most likley has a 205 TC in it if the 14 cam in it from the factory I would need to see a pic of the output. The one way to tell is the NP 205 has a little round cover on the back with three bolts, otherwise its a 203. Thats a killer combination if you have it. With 179K on the meter you minght think about a crate motor from GM. If you dont have the cash I would check the compression and if all cylinders are good maybee recam it and an intake, I have had great luck with the Edlebrock Performer cam and intake.

it does have the little round cover with 3 bolts on the back, so I guess it's a NP 205. Do you think a crate 350 will be strong enough to haul occasional heavy loads? Where's a good place to get them for a reasonable price? Thanks for the info!

What do you consider heavy loads?:skull:

Well, considering it has been converted to a Dually and has a flatbed, I was thinking between 6,000 and 7,000lbs in the bed itself, or possibly being able to pull a 10,000lb trailer. Thanks

to get more power put a cam in, domed pistons, headers, high flow cats, and duel flowmasters, you could also get a 4 barrel for it and put on some cylinder heads that are closed chamber probably from the muscle car ara amd put in a NV4500 this is a killer 5 speed go to www.NV4500.com for more info

you might consider building a stroker motor. It also depends on how NM is with smog laws. I dont know if the 3/4 tons had cats in 77. If you are geared right I dont think you will have much of a problem towing 8-10k #'s with a mild build on a 350 as long as you dont tow that much everyday.

Side note: I have a 383 in my 74 and if I had the brakes to stop 10K pounds I wouldnt blink an eye about hooking it up.

It was registered here and has no cats, just dual exhaust straight out from each manifold. We are thinking about getting a crate 350, edlebrock intake, new carb (which do you recommend?), headers (again, which are best for HP and torque for price?), and dual flowmasters. Thanks again

I think you are on the right track with the crate motor. For a carb I would stay with the Q-jet you can get it from whomever you want ie. Edelbrock, Jet Perf. etc. all good carbs and as long as you stay with one of the big names I dont think you will have a problem. As for the headers They wont do anything for you uless you wind that motor aver 4grand, I dont run headers I am after the torque which comes at a lower RPM. As for the muffler you get it all depends on how loud you want to be, I wouldnt go any bigger than 2 1/4 on a stock motor myself but its up to you. I have found bigger exhaust robs power on a stock motor just my own experience. my .02

have you run a compression check on the motor thats in it yet?

We haven't run a compression check, but the engine knocks pretty bad so I'm thinking it's about to go. I guess we will start looking for a good price on crate motors and go that route. Have you seen my post on the loose shifters? What can I do to fix them from moving so much? Thanks

I havent had a 205 in a while and havent had that problem with my 465 so my input wouldnt come from experience. I elect to take the fith on that one :D