1971 K20 Rat Rod Resurrection

[chewiebarker]

Agreed. Early winter the plan was to pull the engine so I could work on it in the garage, so I pulled off the front grille and bumper, etc. to get access, then LIFE got in the way. The truck itself is TOO BIG to fit in my garage, so I parked it and couldn't legally drive it without bumpers. Then the snow came and that was the end of that plan. Glad spring is finally here and I can get back to it!

[chewiebarker]

Just ordered a poly gas tank and I already have the sending unit. Along with replacing those, I am going to rebuild the carb using Cliff's High Performance kit and book. Hopefully I can get this thing running better, and eliminate the hard starts, before moving on to the next thing. Glad the good weather is back!

[Juiced06GTO]

Hey I had emailed you a few weeks ago when you had this listed for sale. Glad to see you are keeping it and bringing it back. I ended up picking up a 69 C10. My sheet metal showed up yesterday so work will start this weekend hopefully. We'll have to get the two trucks together at a show sometime!

[chewiebarker]

Sorry didn't see the email. I half-hearted listed it. So much to fix I just don't know what to do. In the meantime I will move forward.

Like today! Finally! I fixed something that actually mattered on this beast! I got an MTS poly fuel tank on Ebay for $170 delivered. I had an LMC sending unit that the previous owner gave me when I bought the truck. Spent a few hours today getting the old tank out (which looks original to the truck) and the new one in, hooked up, and fueled! Success! Now I know what12 gallons of gas looks like on the fuel gauge (see pic)!!!

The old tank was in pretty bad shape and leaking from the seams. Also, I spilled a little fuel getting it out - and it was slick and blackish. No wonder I couldn't get any oomph when I stepped on the go pedal....

Once the clean fuel was in, the truck started right up, no more choppy start, and the tone of the engine/pipes is totally better now. Much smoother! The engine revs up and winds down without any glug. There is a noticeable snappiness to the acceleration as well! If anyone is driving around with an old tank, I highly recommend swapping out. Your engine will love you for it!

[chewiebarker]

Woohoo! Just got a rot free Tailpan shipped from California. Bought it from Cheyenne Shortstep on this board. Don't know how I would have found one around here that isn't all rotted out. This will allow me to reattach the tailgate hinges to the truck so that my tailgate doesn't flop freely.

Now....just to figure out how to swap it in without tearing apart the whole truck.....

[rusty76]

Don't know what I'm looking at but that surely looks likes fun ahead.....oh boy.

[chewiebarker]

Originally Posted by rusty76

Don't know what I'm looking at but that surely looks likes fun ahead.....oh boy.

This is the rear most part of the floor bed that sits on the frame. It is like the threshold to the cargo area. It has two slots in it that the rear tailgate hinges slip into and bolt to brackets underneath. My brackets rotted out completely, as well as the pan itself, so I need to replace it. It will be an adventure I am sure!!
Posted via Mobile Device

[rusty76]

Cool man. I thought that might be what it was but wasn't really sure. Good luck!

[LockDoc]

-
We like progress..... Way to go!

LockDoc

[chewiebarker]

Damn. I just happened to be looking into transmissions and rear ends, thinking about trying to improve highway driving and I come across the fact that I think the P.O. screwed me once again. Apparently, what is supposed to be a 'hypoid, full floating type, ratio 4.57" rear axle ISN'T. Being a complete newbie, I had no idea that this rear is only an 8.5" 10-bolt rear - which is NOT the original rear axle for the 1971 K20 Suburban!! Am I wrong on this, anyone??

[chewiebarker]

Ah Ha! Well, it was driving me nuts and I kept looking at pics of 10-bolts and the axle housings didn't look the same, so I went out an checked the stamping on the differential. Based on some googling it is an Eaton! Good to know. looks like it is at least 3/4 ton.

[bigrigpardo]

yup that's an eaton ho52

[chewiebarker]

Even better! Based on the pics in this thread (thanks jbclassix!!) http://67-72chevytrucks.com/vboard/s...d.php?t=536119 it looks to me like someone before me already swapped the brakes from the 14 bolt onto the Eaton! Will have to go back out and confirm it tomorrow!

[twistedchevy]

It has load bolt so it should be a H072

Very limited in gears. 4.10, 4.56, 5.13(I think). And nobody is making gears for them

[chewiebarker]

Turns out the casting number on my intake manifold is not necessarily for a corvette. It is 3973469 which is all passenger cars, Cast Iron, 270 Hp for a 1971 350sbc. So perhaps it is original...

I am certain however that the carb is not. It has an identification number of 7042237 which is apparently for a 1971 Cadillac 7.7L 472 engine or 8.2L 500 engine. Woah. Perhaps it is a refurb that was metered to work with this application? I think I will be in the market for a new, correct, Quadrajet...

According to the chart below I need to be looking for one that is numbered 7042210.

However, according to cliff's High Performance ID page http://www.cliffshighperformance.com...carb_ID_2.html
The following numbering convention applies:
70 = Rochester
4 = 1970-1975 era
1 = 1971 model year
2 = Quadrajet 4BBL Federal Standards
0,1 or 2 = Chevrolet
0,2,4,6 or 8 = automatic transmission

So I need a carb with one of the following numbers:
7041200, 7041202, 7041204, 7041206, 7041208
7041210, 7041212, 7041214, 7041216, 7041218
7041220, 7041222, 7041224, 7041226, 7041228

Does anyone know whether the variations on the Chevrolet numbering or the automatic transmission numbering matter? In other words, does it matter, for correctness, whether I get a carb with any of the 15 numbers above, or will any one do?

Thanks

[chewiebarker]

so....according to carbs unlimited a carb with the number 7041200 is for a 402 of 454 engine
http://www.carburetion.com/Number/oe...number=7041200

yet, a carb with the number 7041202 is for the 270hp 350...

http://www.carburetion.com/Number/oemnumber.asp

So, answering my own question, it apparently does matter. I will have to investigate further.

[chewiebarker]

Based on searching the database at Carbs Unlimited (links above) I was able to identify the following carb number as correct for a 1971 K20 Suburban with a 350 - 7041208

Does anyone know whether the other carbs listed below for use with 350s (but in other applications) is more appropriate given that my vehicle has an intake manifold that is #3973469 GM2 ?? Should I go with the truck carb or the others given what I know? Does it even matter or all they all the same at this point of specificity?

Help a rookie out!! please.

[chewiebarker]

Fantastic detail on this guys' page TuningByLars (it is a pdf)
http://www.google.com/url?sa=t&rct=j...98717601,d.cGU

[Bigdav160]

My '72 Corvette has a '72 truck quadrajet on it. It seems to hook up and function just fine

[rusty76]

Glad you are able to start decoding the past. It amazes me how much a vehicle can go through with different owners, lol.

[Average Joe]

Have you thought about just having your carb rebuilt specifically to your rig? I realize it may not be numbers matching but it would probably perform better. Google Sean Murphy Induction in California or SMI. Cliff Ruggles is another name that comes to mind but I think he is at least a couple months out.

[chewiebarker]

Average Joe,

I didn't realize that was really an option. It doesn't really matter to me whether I have a numbers matching carb, so long as it is properly working. I am driving my Burban daily now, as I am in-between cars, but I don't know how to determine whether the carb is operating properly/efficiently. Once I secure a new vehicle for daily driving, I am going to pull this engine for rebuild. It will take some time, so perhaps I will contact Cliff and ask questions.

Thanks

[Juiced06GTO]

How are you making out with the truck? I have another big order showing up from GMC Paul's, but haven't made much progress on mine. Who knew having a kid would eat up so much time hahaha!

[LockDoc]

Originally Posted by Juiced06GTO

How are you making out with the truck? I have another big order showing up from GMC Paul's, but haven't made much progress on mine. Who knew having a kid would eat up so much time hahaha!

That has put the skids on a lot of peoples projects..... You just have to remember when they are past each step in their lives they can never go back so you have to enjoy them day by day.

LockDoc