Author Topic: Engine rebuild... what's what with all those codes...  (Read 2223 times)

0 Members and 1 Guest are viewing this topic.

Offline MontrealY82

  • Jr. Member
  • *
  • Posts: 19
  • Referrals: 0
Engine rebuild... what's what with all those codes...
« on: August 18, 2007, 11:58:23 AM »
Allright, here's the deal :

77 T/A with 4 speed manual, W72 is gone  :'(

Right now, my car has a 350 in it and I have a 400 sitting next to it.

400 : casting # 481988
         code YT
         date code L104 which would make it a 74
         heads are 5C-8 driver date : L204 pass. date : A105

350: casting # 488986
         code YB
         date code K133 which would make it a 73
         heads are 46 driver date : K123 pass. date : K153

Carburator is Quadrajet for GM code 7045264

Here are my questions :

I want to rebuild the 400, of course, with mild upgrades, should I keep the 5C heads or use the 46 heads?

How much of the 350 parts can I keep? water pump, pulleys, alt bracket, flywheel?  I already contacted a guy here with a good reputation for rebuilding engines and he asked me especially about the harmonic balancer, the pulleys  and the flywheel. Can I take those of the 350?

Quadrajet is supposed to be the original one from the car, even if the last digit indicate an auto tranny but apparently they didn't always follow that rule... Should I keep it or swap it, if it's real, it would be a 800 CFM Quadrajet?

Thank in advance

Jeff


         

Offline Joker (告r茺agon)

  • Lifetime Member
  • *****
  • Posts: 4994
  • When you think it can't get any worse...God laughs
  • Referrals: 0
Re: Engine rebuild... what's what with all those codes...
« Reply #1 on: August 18, 2007, 01:05:44 PM »
Well, I can't help you much on which heads to use or specifics on the Pontiac engines. But I did run the carb numbers over at Fred's page and it comes out to be off of a 400 auto alright. But it's from a '75 Federal A,B or G body.
Larry


Offline MontrealY82

  • Jr. Member
  • *
  • Posts: 19
  • Referrals: 0
Re: Engine rebuild... what's what with all those codes...
« Reply #2 on: August 18, 2007, 01:35:16 PM »
I was on the wallace racing's page looking up all those numbers and you're right, the carb is not original. Even the 400 block and the heads are a mismatch.... Only the 350 seems to be a match...

So, can I match any of those parts to make a decent 400...?  :)

Jeff

Offline Joker (告r茺agon)

  • Lifetime Member
  • *****
  • Posts: 4994
  • When you think it can't get any worse...God laughs
  • Referrals: 0
Re: Engine rebuild... what's what with all those codes...
« Reply #3 on: August 18, 2007, 03:14:48 PM »
I was on the wallace racing's page looking up all those numbers and you're right, the carb is not original. Even the 400 block and the heads are a mismatch.... Only the 350 seems to be a match...


Not neccessarily. I'm comparing the chart at Wallace and the one at Fred's and Fred's has a few more details. He lists an early '75 block with the same casting number and engine code that you have. And since your's has a date of Dec. 10 '74 that would fit. That would be the 185 hp 400 and it would have had 5C heads. AND it would have had a carb number 7045266. The carb you have would have been for a code ZT engine of the same year wich according to Wallace is the smog equipped engine. So maybe the original carb for the engine was replaced with one for the same year.

I also found this for your heads.

5C-8 1975 400 4bbl, 2.11/1.66" valves, 4.960/4.949" valve length, 30/45 degree seats, threaded studs, 101cc
5C heads were installed on engines until around mid 1975 then dropped (No explaination given. But I'm sure one of the Poncho guys here will know.)

46 are 350 2bbl/4bbl heads with about 86cc, smaller 1.96/1.66" valves and pressed studs.

The date code and engine code for your 350 would make it a '74 (Nov. 13 '73) 155 hp 2bbl.

Depending on what you're looking to get out of it and what your budget is you may be able to use the 5C heads and the 400 to get what you want.
Larry


Offline MontrealY82

  • Jr. Member
  • *
  • Posts: 19
  • Referrals: 0
Re: Engine rebuild... what's what with all those codes...
« Reply #4 on: August 18, 2007, 04:24:47 PM »
Thaks for the info... Where's Fred page?

I'm looking for a strong and reliable engine, 400 to have a somewhat close to original motor feel. I want to warm it up a bit, maybe close to 250 - 275hp, I don't want a fire breathing monster.

I still wonder if I can transfer parts like the flywheel, water pump, harmonic balancer from the 350 to the 400. I think I'll end up pulling the 350 out of the car and bringing both engine to my engine guy and having him make one out of the 400...

Jeff

Offline MontrealY82

  • Jr. Member
  • *
  • Posts: 19
  • Referrals: 0
Re: Engine rebuild... what's what with all those codes...
« Reply #5 on: August 18, 2007, 04:26:02 PM »
I think I found the page... Is this it?

http://www.teufert.net/

Jeff

Offline Tbird

  • Member
  • **
  • Posts: 341
  • Referrals: 0
Re: Engine rebuild... what's what with all those codes...
« Reply #6 on: August 18, 2007, 06:48:40 PM »
While your at it look for some M/T hemi heads for me to put on a Poncho engine build.

Offline Joker (告r茺agon)

  • Lifetime Member
  • *****
  • Posts: 4994
  • When you think it can't get any worse...God laughs
  • Referrals: 0
Re: Engine rebuild... what's what with all those codes...
« Reply #7 on: August 18, 2007, 08:00:17 PM »
I think I found the page... Is this it?

http://www.teufert.net/

Jeff

Yep! That's it.

I don't know if the balancer will work from the 350. And I said not long ago to someone else - I wouldn't trust an old one anymore with all the failures I've been hearing about.
Larry