[69swb]

Folks help me out - i spend tons of time reading this forum and others, I feel like I’ve tried everything, and it’s tough for me to ask for help but this trucks got me feeling like I’ve got more dollars than sense.. Pretty frustrated with my daily driver. It seems to overheat, stalls at idle, poor throttle response, gets harder to time the longer the truck sits with the fans running, seems to get really hot when running the timing procedure.

Truck: Bought this thing in september, it ran great in cold New York, not doing so well down here in 90 degree weather. 1971 350 2bm from an impala, 478 heads, performer aluminum intake, hooker headers with some cheap dual pipe exhaust job but no exhaust leaks, edelbrock 1406 600cfm. This thing sees some serious heat soak.

Cooling: I installed a cold case radiator with 12” electric fans, aluminum panels above the radiator and core support so the fans pull in more fresh air. It sees enough amps, but the shroud seems kinda tight - cold case claims that’s for better suction at idle. 180F thermostat. Temperature meter doesn’t present correctly - i put a lectric limited sender in it with no teflon tape, replaced the lead in the engine harness, have high heat wire loom around that wire under the headers, the sender itself has proper resistance and grounds well, cleaned the four posts on the temperature meter itself, but none of that changed the temp meter’s behavior. Thinking about replacing the temp meter and printed circuit board in the dash. Also thinking about putting the original shroud and clutch fan back on.

Fuel:Put a 2” phenolic spacer under the carb (2” might be a little much but don’t think that’s my problem.) . I rebuilt the carb, first with a cheap knockoff kit then with an edelbrock kit and set float to 7/16. Tuned AFM to highest steadiest vacuum with a vaccum guage - best i can get at most timing settings is 16-17. I’ve replaced the old fuel lines from the pump up to the carb, have a pressure gauge inline, fuel pump seems fine.

Air: oiled spectre air filter. Replaced header gaskets, brand new mufflers, no exhaust leaks.

Spark: I’ve spent the last few weeks messing with the ignition system. NGK spark plugs gapped to .45. MSD superconductor wires cut to fit, loomed really well (pretty proud of that), then messed with the timing. Had an old delco remy HEI in it, I replaced the broken vacuum can with an adjustable one and put it on the middle adjustment.i used the procedure in here to make sure my balancer’s TDC mark was accurate, it was only off .53 degrees but i marked it and use my new mark. Did all kinds if timing - wondering if I’m making an error here. So with the old HEI I put new moroso curve kit in it, the weights were not upside down and moved all the way in and out easily on the bench, i used the lightest springs. Vacuum removed and plugged, i turn the idle screw up until the timing light read 3000 rpm, 36 degrees total advance. Turned it back down to as low as possible, and initial advance only read 26 (10 degrees mechanical advance seemed wrong, seemed low), vacuum installed into manifold vacuum, brought it up to 53 (27vacuum advance, a little high). Troubleshooting by replacing parts is poor form, but this is where I started getting frustrated, so I installed a pertronix Ignitor II with their ignitor II coil. No ballast resistor, coil gets 12.4v, timed it to 36. Mechanical advance provides 24 degrees. When I get the timing to a good spot at total advance, I bring the idle screw back down to ~800 rpm, attach vacuum advance to manifold vacuum, then turn the idle back down to ~800 rpm.

As the truck gets hotter, it won’t idle unless I advance the timing more. Last weekend With the delco remy HEI I got it advanced as much as I could without pinging, drove the truck for ~4hrs that day, and it still seemed to be overheating past where I could advance the timing.

Doesn’t like to idle, sputters on throttle from idle (so i switched to ported advance to get home which seemed to work, but then really didn’t like to idle.

I’m thinking I have an overheating problem more than a timing problem.

I need to get the temperature meter fixed correctly. Probably just going to run a mechanical temp guage for now to be sure.

What jumps out to you guys? This is my first carbureted vehicle, i want to daily this thing in the georgia heat - can I get it running well enough for it to start up at 5am when it’s 50-60F and also after it’s hot in 95F heat of the afternoon.