Base plate APT screw removal success!

[the69riv]

First post, been searching and reading for a few weeks now. Rebuilding a 7029241 Qjet that is on my 69 Riviera, I purchased a HP kit, primary bushing kit and new pull off. Almost finished with the rebuild and I discovered on the forum about the base plate APT on this model and the custom screw that Cliff has to make them adjustable. Purchased the screw this morning and figured it was time after work this evening to bite the bullet and get the factory screw out.
Thanks to a few tips on here I got started on removal. Heat, penetrant and plenty of PATIENCE is going to be your recipe for success here. Did I mention PATIENCE?
Used a flat tip burr bit to remove the staked portion of the plate holding the plug cover. Then carefully drilled the plug with a small drill and popped it right out.
I then clamped the base plate in a vice with jaw protection with the screw location up so I could fill that bore and constantly keep penetrant on the screw.
That screw was stuck big time! But slowly with heat and penetrant and a good fitting screwdriver I managed to finally get it to move the smallest amount after 30 minutes or so of trying back and forth. Kept working at it and that small amount turned into an 1/8 of a turn, then a 1/4, then I got a 1/2 turn out. I couldn’t seem to get any progress on moving the screw in further but hey, it was on its way out! I removed the baseplate from the vice and worked on the cavity on the other end of the screw with penetrant and let it soak for a bit. Put baseplate back in the upright position in the vise and started to work on getting more than 1/2 a turn. It helped and managed to loosen up a little more when going from one extreme to the other.
Patience and trying not to push it too much in either direction, another 30 minutes or so that screw was out of there.
Threads in the base plate look good enough as is but I will probably run a tap in there by hand just to be sure.
Might not seem like much but not having to fight and end up drilling out and tapping is a big victory in my opinion!
Thanks for reading my ramblings!

[the69riv]

New custom APT screw from Cliff arrived (thanks Cliff!)

[Cliff Ruggles]

Good news that you were able to get it out and replaced.  I'm pretty good at it since I get a LOT of practice.  It's never a 100 percent success rate but IF you follow the steps mentioned in your post you'll get most of them without issue.  The "key" to success is to make a good fitting flat blade screwdriver and don't try to force it until it's ready to come out.........

[Shiny]

Small world.... or not....

Cliff guided me on the same issue about 15 yrs ago and helped me save a Buick carb that is now on my Pontiac 350.  I ended up drilling and tapping but his help kept me from destroying the base.  Cliff providing the replacement APT screw was like winning the lottery.

Hope your carb works out well for you!

[the69riv]

The carb has worked out awesome. Not long after the carb I rebuilt the distributor and just got everything sorted in the last couple days. With Cliff’s advice and taking my time to make sure everything with the carb and distributor were working correctly, I now have a very nice running engine. The Riviera now accelerates as smooth as any fuel injected car I’ve owned and definitely the best carb/points setup I’ve ever had. The best part is all settings ended up being basically what the 430 had in 69. All my parts on the carb were from Cliff and the distributor was rebuilt with all good quality NOS Standard Ignition parts except for the points and condenser being new Accel units.
It idles at 550 with over 19 inches of vac and has all that Buick big block torque to make it a very nice driver.
Cliff always had straight, no bs answers for all my questions. So refreshing in todays sea of misinformation and people on other forums pushing their agendas and opinions without actual real world experience.

[Shiny]

That's a good ending and I'm happy to hear about your success.

Sounds like a nice car that makes you smile...  nicely done.

[Cliff Ruggles]

Good news and glad to help out. 

If you follow advice from most self proclaimed "gurus" on distributor stuff you'd have a junk set of MrGasket light springs in there and wouldn't be using the vacuum advance.

For some reason I'll NEVER understand with these things is that folks think for some reason that these engines need ALL the timing right off idle and no additional timing from the VA.

I also see a lot of folks switching over to manifold vacuum instead of leaving it on ported vacuum like the factory did way back then.  High compression engines with well chosen camshafts will not like, want, need or respond well to a butt-load of timing at idle speed. 

Save those mods for your fresh 350 SBC engine with dished pistons, 882 heads, RV cam and .060" thick head gaskets.  It's going to want ALL the timing you can put to it at idle and everyplace else to make a whopping 200hp!......Cliff