It's actually used well beyond '69.
The small block brace is #3965589; big block brace is #3965588.

 

There are 2 different starter braces for small blocks. They vary depending in the flywheel outside diameter.

I have no idea about big blocks, but in every case - if engines have different flywheel diameters, they need different starter braces.

 

Both OE starter support braces are designed to fit properly with OE old fashioned, heavy, direct-drive Delco Remy 10MT starters

OTOH, they're wholly unnecessary with modern, much lighter PMGR aka PG260 style starters; old OE braces won't even fit without modifying them first.

 

SO played with it a good amount this weekend. The rear/secondary where leaking fuel the whole time it runs... so something was stuck in the needle. Picked up a Holly 600 rebuilt kit, and a new Fuel filter.

Rebuilt the carb blew it all out port wise, jets (65), rebuild Accelerator pump, checked Vacuum secondary function, new gaskets all around. Fixed that issue, car fired right back up idles and no more smoke.

I was hoping that was the main cause of the miss when driving it. It runs but still has studder/ miss. Idles and fire right up though. also replaced the plug wires. still has miss. but its runs and drives at least now so i can move it around and on and off my main lift. Looking at fuel too while it did not smell bad, it did not look great, so drained that, added 2.5 of 93 back in, and then drained that too. now it has 8 gallons of fresh 93.

Still has miss, we stirred some stuff up in the tank as I can see the new fuel filter coming and going with fuel, It was SOILD fast fill before we messed with the tank. The tank has been replaced so its not old, was just older fuel in it. Its not starving for fuel, the carbs bowls are staying full. Once we get it running well and ran a gear or too that maybe a issue but currently its keeping up.

Next up is starter for more reliable starts and a compression test I guess? Open to other ideas to get the miss fixed. Short video of me driving it down road can hear it stumbling.

 

Have you checked for spark? My '73 was idling rough, distributor had a Pertronix Ignitor module in it and that was the issue. I got a compression test kit that included two inline spark plug testers, it was easy to plug those in two at a time and check all the cylinders. Two were not firing because little magnets had fallen out of the Pertronix sensor.

Yours is some other kind of electronic ignition module so don't know if it has any common failures.

 

I have placed the timing light on all 8 wires and it's getting a signal to fire the timing light. I have not put an inline Light to check each. I have 2 or 3 of those so I can check a few at a time. But when I had a timing light out checking I did clamp it on each wire to make sure I had something at least. It idles fine, just once loaded its missing.

 

Maybe I’ve missed it somewhere, but what is your ignition timing set too? And how much vacuum advance?

 

That's a good question. Mittens, are you sure it's miss firing or might it be "trailer hitching" (a sort of bucking sensation)?

Mittens, one way to spot spark plug wiring failures is to look for spark jumps to nearby metal while the engine is running in a dark location. You may be able to hear the spark click when it jumps.

 

Its not bucking like a big cam car if that's what you mean. its idling fine, and as you start to take off drive through the gear it just has some off/on missing breaking up. it's not smooth with the power.

I checked timing and it has an aftermarket Lower pully on it. So it shows 0 to 60 degrees on the pully. Then it also has the factory timing pointers on the block.

The way I understand it, you use the Zero on the pointer and the marks on the Pulley. Showing me around 12 degree advance at idle. I have not reved it and checked the vaccum advance part. Or thats not correct haha. Open to instructions. My 66 was just normal. I adjusted timing till 12 which the gauge only showed 10 so guessed the 12 mark/ with the TDC mark on pulley.

 

Are you checking your initial timing with or without the vacuum advance connected? 12 isn’t a bad number assuming that’s without vacuum advance. If it is then your actual initial timing might be 0 or even less.

I would email Lars a v8fastcars@msn.com and ask for a copy of his timing papers. Modern gasoline formulas require different ignition specs than when these cars were new, and since you’re using 93 octane your car can probably take a bit more advance.

 

CRAP. I forgot to pull the vacuum line off the advance when testing. (Pretty sure when setting it on the 66, I unhooked it and plugged hose. Set car to 12, and then reconnected it)

so if its reading 12 with it hooked up it could be way retarded? Sorry my ignorance but would timing being way retarded cause shuddering but stull fire up great?


Most of my knowledge base is LS/LT stuff so these old cars I am learning.

 

I listened to the video. Sounds like a bad camshaft lobe to me. Try removing one spark plug wire at a time and drive the car. Check for rough running, the Cyl. with the least amount of difference in drive-ability is the bad Cyl. Because it is not contributing as much as the other Cylinders. Go to that Cyl. and check the amount of valve opening of both valves. my guess is an intake valve is not fully opening due to a worn camshaft lobe. A compression test will not show your problem if it idles correctly. Off idle, the intake valve may not be opening enough to properly fill the cylinder, hence the miss.

 

Depends if your vacuum advance canister is hooked to ported or manifold vacuum. Ported won't be a problem checking timing but manifold yes, you need to disconnect and plug hose to Vac. Adv. canister.

 

I would remove and cap it when checking regardless though. And if it’s not hooked up to a manifold (has vacuum at idle) source I would make sure it is afterwards.

 

Interesting for sure. I can see how that would work idle vs throttle wise. But could that not also be a lifter issue? if one is not pumped all the way up, its causing less lift? would that not be more likley then a strait up worn out lobe? I saw this as so far in what we have been finding whom ever put the car back together and painted it at least spend some time and money so seems pointless to install a bad cam/motor. I guess he could have with out knowing too.. anything can happen.

 

Will be checking timing again with Vacuum disconnected.

Can pull valve covers and measure lift on valves if I have too. but that brings me back to the Lifter vs lobe question

 

It's quite possible it's just a collapsed lifter or a bent pushrod, but the heat treating of camshafts lately, has been poor. Combined with the reduction or removal of Zinc in motor oils. Makes for an undesirable condition. That's what leads me to question the camshaft.
Once you find the offending Cyl., check the rocker arm nuts and see if one of them is turned in more than the rest. This will confirm a camshaft/lifter/pushrod problem.

 

Does anyone know what type of electronic ignition module this is?

 

It looks like SE Breakerless

 

Thanks, that should help to know what's in the dizzy!

Here's a thread with a link in there that supposedly includes troubleshooting steps for it. (I didn't read it.)

Breakerless Ignition - CorvetteForum - Chevrolet Corvette Forum Discussion