That being said I’d have to remove the distributor and haven’t seen anything on here about reinstalling it without having to go TDC. Is it possible to simply uninstall it, fix the vacuum leak, and reinstall the distributor since the engine won’t be turned?
Greetings Herbk,
Welcome to the GMT400 forum.
Been where you are. If you do the following sequence of events, you should have no problems
with the distributor R&R:
1)
Disconnect the battery.
Prevents accidental cranking of the engine while the distributor is out. This is 99% of the reason
why I'd be forced to locate TDC on the compression stroke after the fact on a job like this. :0)
2) Pick a spot that you can easily see, and using some touch up paint / bright nail polish (or even White Out)
make yourself an alignment mark between the base of the distributor and the adjoining intake surface.
You will use this to make sure that the distributor goes right back to where it was originally during reinstallation.
3) Remove the distributor cap and mark the distributor housing right where the rotor is pointing.
(So that you can verify proper rotor clocking post reinstallation.)
4) When pulling the distributor, note both the direction (CCW?) and the total rotation of the rotor that
occurs during removal. (Due to the curved drive gears between the dizzy and the camshaft.) During reinstallation
you will need to re-establish this same rotor clocking before you go to drop it back in.
5) Since the engine was never accidentally turned while it was apart (thanks to you performing
step #1) ...you should end up with a no muss, no fuss distributor R&R to facilitate other maintenance.
6) After all is done, reconnect the battery & (once the fuel shows up) it should start like it never
came apart.
Note: A fresh intake manifold gasket can cause the intake manifold to set just a wee bit higher than
before. IF the distributor was perfectly timed prior to disassembly, this new vertical position may cause
the initial (base) timing to be off a degree or two. (Thanks to those curved drive gears.) We're not talking a
gross error that would prevent the truck from restarting, but if you are going to go to the trouble
of installing a new intake manifold gasket, why not try to get the engine to run the best it can?
In English, you may want to have a timing light on hand to verify proper ignition timing after the fact.
(Bonus points for figuring out how to check the timing *before* you perform the intake regasketing.)
****
Of course, taking before photos of a bigger project like this help minimize the self-doubt when it's all
going back together. And if you get stuck, there's plenty of folks in here who can help.
Best of luck with your repair effort.
