Search results

  1. 75gmck25

    Cargo and Dome not working

    The wires run under the kick plate on the drivers side door. Insulation got very brittle on mine and I had to replace that section of wire.
  2. 75gmck25

    First time replacing intake manifold gaskets

    My engine developed a noticeable tick, and I used an engine stethoscope to determine which cylinder. Pulled the valve cover and it turned out to be a polylock on the rocker that loosened up and it was the pushrod rattling. Sometimes a very small exhaust leak can also sound like a tick. Check...
  3. 75gmck25

    First time replacing intake manifold gaskets

    It’s part of the hot air choke on a Quadrajet. The choke mechanism has a couple small tubes that connect to that device, and it pulls air through it to heat and operate the choke. It’s not needed if you have an electric choke. IIRC, my Edelebrock intake came with a choke block-off plate for...
  4. 75gmck25

    New guy with a ton of general questions...

    My camper wiring harness is a separate wire bundle (brake and turn signal wires, and ground) that runs from the engine compartment down along the drivers side frame rail to a point under the bed. At that point it would have been connected to the camper wiring. I assume that trailer wiring...
  5. 75gmck25

    85 K20 4X4 6.0 6L80E swap. What are my fuel delivery options. Rear tank?

    You can buy rubber EFI fuel hose, spec SAE J30R9, and it is rated for up to 100 psi. It also holds up well to ethanol fuel. The 87 tank option should work fine, but you will need a pump in each tank, and the switching valve for dual EFI tanks.
  6. 75gmck25

    Power steering pump

    The stethoscope I have has a tube on the end, and a couple extensions.So far I have only used it to track down a tick from one lifter. Turned out the adjusting nut had loosened.
  7. 75gmck25

    First time replacing intake manifold gaskets

    Definitely remove the plugs if you plan to turn it over by the crankshaft bolt. You do not want to strip that bolt. You can also use a tool to turn it over by the flywheel teeth, after you remove the inspection cover. Or you can get a tool/gadget that bolts onto the three bolts on the...
  8. 75gmck25

    Hello. And weight Q for title in Texas.

    The info is out there in some book, but I can’t tell you exactly where. As a reference, my 1975 3/4 ton K25 goes across the scale with two passengers at about 5300 lbs, so empty is probably about 4900-5000 lbs. My guess is that your suburban would probably run about 500 lbs heavier than a pickup.
  9. 75gmck25

    454 460 horsepower swap into a 1987 V10 with 700r4

    That’s a lot of horsepower for a 700R4 unless it’s been beefed up quite a bit. You need to talk to a transmission builder. I am surprised you could get a 454/460 HP with that mild cam unless it also has other significant upgrades. Are you sure of the engine specs? I would also look for gears...
  10. 75gmck25

    Do I need an Alternator upgrade?

    I assume that by ‘86 the 94 amp was common. However, even the original 63 amp on my ‘75 was an option upgrade that I think was included with A/C. The 10si maxed at 63 amp, so if you have a 78 amp it is a 12si. Both will mount and wire in the same. Take a look at the madelectrical.com site...
  11. 75gmck25

    Do I need an Alternator upgrade?

    Doesn’t sound like you need it. I’m using a 94 amp 12si right now, and never see any evidence that it’s not enough. I added the relay wiring kit to my headlights, which was the only high amperage thing on my truck. Higher amp alternators are needed to support big driving lights, high...
  12. 75gmck25

    I'm sure it's an age old question, K 20 ride quality improvements.

    My K25 is 8600 lb GVW, and it definitely rides better with about 1000lbs in the bed. In that era GM did not use any type of factory progressive overloads, so the full GVW load capacity is there all the time. It’s great for hauling loads.
  13. 75gmck25

    AC Head Control Options

    If you mean the dash controls, I don’t think total aftermarket would work. The replacement controls from LMC and other vendors do not include the large molded plug on the back of the controls, and that is where the vacuum lines connect. On an A/C truck all the blend doors are vacuum operated...
  14. 75gmck25

    EFI rated fuel plumbing solution

    J30R9 is a specification/rating, not a brand or hose design. It’s rated for 100 psi pressure, and resistance to the new fuel. It looks a lot like regular fuel hose, but is a little harder to bend. J30R7 rated hose also handles the new fuels, but is for max 50 psi EFI.
  15. 75gmck25

    Are these vacuum ports?

    AFAIK, my my Edelbrock intake came with a choke stove block off plate, and I think they sell aftermarket replacements. My aluminum heads don’t have an exhaust crossover, so it I don’t think it would do anything anyway.
  16. 75gmck25

    EFI rated fuel plumbing solution

    Amazon and other vendors sell SAE J30R9 fuel hose, which is rated for high pressure EFI and modern gas. Local stores also carry it, but it’s usually much cheaper to buy lengths of it (20 feet?) from online. They also have EFI hose clamps, which are made like band clamps, so they don’t cut...
  17. 75gmck25

    Ever dealt with GM crate motor warranty replacement?

    Do some simple troubleshooting first. Pull the valve cover and check pushrods and rockers. Maybe have someone crank it over while you watch the valve train. You may also want to pull the intake and check for collapsed lifters, antifreeze leaks, etc. If no problems are visible in the valve...
  18. 75gmck25

    PCV manifold or ported vacuum?

    What is the number on the side of your Quadrajet? Mine is a 1980 model, and it does not have that #4 connection. PCV hose definitely does not go to the charcoal canister, but it is possible that the canister vent is T’d into the PCV line. PCV hose is connected to a 3/8” fitting on the...
  19. 75gmck25

    New crate engine oil priming/ ignition timing impact if the distributor is mis-installed

    Does your new engine have a a flat tappet cam or a roller cam? Flat tappet cams require break-in, and if you have never done it before it can make you very uncomfortable. Standing next to an engine that is running at 2500 rpm for 20 minutes to break in the cam is really noisy, and it feels like...
  20. 75gmck25

    74 k10 going 55 mph is at 3,500 rpm

    My similar ‘75 K25 with 4.10 gears, np203 and TH350, and stock height tires (245/75R16E - about 31”) runs at about 2800-3000 rpm at 60 mph. I doubt I’m getting much over 10 mpg. You should be able to fit up 33” tires with no lift or fender trimming on a K10, and that would help. Also make...
  21. 75gmck25

    Air conditioner compressor wires

    IIRC, on my compressor the black wire is grounded to the body of the compressor.
  22. 75gmck25

    Timing light recommendations

    I’m using an Innova light with setback dial and a tachometer readout, and IIRC it was about $100-110. It seems to be good quality, and it has all the info I need in one package (both timing and rpm) to check my vacuum and mechanical advance. I first tried buying a similar light from Harbor...
  23. 75gmck25

    Dash/radio lose power on ignition wires

    It may be the ignition switch out of adjustment, or the rack and rod mechanism has broken. Some of the switch contacts may be only making a partial connection. The actual electrical switch is mounted on the column about where it goes through the dash. The key switch has a toothed gear on the...
  24. 75gmck25

    Fixing vapor lock now that I barely made it home, experience with 3 port filters?

    I’ve never see a filter with a return port, so I don’t know how well they work. However, the mechanical fuel pump with a return line was used on many GM vehicles, and the pumps are not expensive. I would go with the OEM solution. Rubber gas line will work to add the line, but you want to use...
  25. 75gmck25

    AC temp control wire

    I’m not sure it’s that wire, but on my ‘75 controls there is an extra wire and two indents on the temperature slider. If you slide it left to the first indent, almost all the way to the left, and the truck is on A/C, you get normal operation of the blower. If you slide it fully to the left...

Latest posts

Forum statistics

Threads
44,391
Posts
956,266
Members
36,679
Latest member
86C25
Top