307 to 403 Olds swap...info please?

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DoubleV

Royal Smart Person
Feb 25, 2011
2,153
407
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Medina Ohio
81X11 said:
- Have not figured out the proper timing yet. Set it like the 307 and it idles really rough and starts hard. Will have to Google the proper timing for the 350.

Your base timing needs to be set to whatever will end up giving you the proper amount of total timing ( which should be around 36 ). Hard starts are usually caused by having too much base timing and/or a high CR. Higher base timing will give you a smoother idle though, so it seems odd you're getting the bad side effects of too high base timing but with out the benefits. Maybe it ain't even timing related. Are you running full manifold vacuum to the distributor or ported? Does it smooth out when you advance or retard the distributor while it's running?

- Temp gauge is dead now, worked with the 307. The hole in the Edelbrock intake is larger than the stock 307 intake. I bought an adaptor at Napa, and it's bolted in, but still getting no reading. Either the sender is bad, or the adaptor raised the sensor up too high to get a good reading....?

The adaptor shouldn't effect it. Doesn't your intake have a proper sized port right next to the one you're using with the adaptor fitting? If so, just use that port.

- I had to install a dropped-base aftermarket air cleaner to close the hood. Put my Rocket 350 decal on it. Looks ok.

What intake are you running? Unless it's an RPM, I can't see how you'd be forced to use a dropbase air cleaner. :?

- Still have to sort the huge wiring mess out. Have not removed the ECM harness under the hood yet, but really want to do that.

Cut the wires where they all join together and 'dissappear' under the AC module. Now all of those wires under the hood are gone. Now remove the passenger side kick panel and unplug the ECM and the other big connector that's for the underdash CCC wiring that route to the drivers side. Remove ECM and pull what's remaining of the CCC wiring under the hood through the rubber grommet in the firewall and you're done. 5 minute job, much longer if you want to remove the CCC wiring intact ( because you need to remove the grommet ).

Stole power from that harness to run the electric choke, and once removed will have to find a new power source.

No you don't. You can still tap into the ECM wiring that's still there under your dash by routing your electric choke wire through the rubber grommet and connecting it to the F pin on the big connector ( the very same connector you unplugged to remove the ECM. This is how mine is. It's clean and required no splicing.

Also it looks like the plug for the disributor is tied into this wiring (?). I have it all bunched up near the evap box near the engine, and it's such a jumbled mess it's hard to tell what goes where. I did install a vaccum-style distributor but did not mod any wires yet.

The 4 prong plug that plugs into the CCC distributor is simply part of the CCC wiring harness that will come out when you remove the rest of it. Note, on at least some years, there's a small 2 prong 'weatherpack' plug in the AC area that plugs into the CCC harness ( or is that the engine wiring harness???? ). If it's connected to the CCC harness, just unplug it.

- Plugged off the PCV port on the carb and installed chrome vent caps on the chrome valve covers. They have the caps with the port for a hose and inline PCV, but don't think I need it. Thoughts?

PCV is important and don't see a need to change anything related to it in any way. You can put a breather on the driver's side valve cover though instead of the factory one with the tube that goes to the air cleaner. I'm currently running the factory breather without the hose which does the same thing as a breather since it still has the openning in it.

- Still have not sorted out how the a/c is supposed to be wired to work.

Do that last. I think it only involves bypassing the AC relay.

- Still need to figure out how to hook the cruise control to the new carb.

You're going to have to add a 'nub' onto your carb linkage to attach the cruise arm. Qjet's rule baby!

That sucks about Terrence's car! :( If theives are caught, they should be able to be tortured at the whim of the victims
 

Intragration

Master Mechanic
Feb 4, 2012
446
1
16
Chicago
I just caught up on this thread, good to see all the progress you've made. On the timing, I've just gone through this whole ordeal myself, it took me a while because I was using some junk parts. You basically want to start from scratch and forget about what any factory manuals may say about timing. What DoubleV said is correct, you're shooting for about 36 total. The challenge in my case was that the factory weights and centerplate were not conducive to getting 20 degrees of centrifugal advance, and the Mr. Gasket recurve kit I tried was absolute junk. I would highly recommend picking up a Moroso 72300 HEI recurve kit, they're available through O'Reilly's. Using the lightest springs, you can check to see how much centrifugal advance your factory weights and centerplate will give you. I ended up using the light springs and the Moroso weights and plate. I set the initial to 15 degrees, and at about 3,000 RPM I get about 35 degrees. Any more than this and I started to get detonation. You will also want to give some attention to your vacuum advance, the one that's in there may give too much, and it may also have failed or be close to it. (could be why it's idling rough...have you checked your vacuum? My vacuum advance went out and it caused a low vacuum reading as a result of the leak.) I replaced mine with a Napa VC1853 and limited it to 10 degrees by making a small aluminum restrictor plate. When you get the timing right, it will definitely make you smile.
 

81X11

Master Mechanic
Oct 28, 2010
362
1
0
Round Rock Texas
Funny you mentioned the distributor. I got home last night and popped the hood, and on a whim turned the distributor. It moved freely....I'd not tightened the hold-down bolt. I turned it counter-clockwise a bit and then went to start the car and it fired right up and idled MUCH MUCH better. Still has a little shake, but not nearly like it was.

Whoops on my part. Got the tool out and tightened the bolt.

Was in the upper 90's....didn't pull out the timing light. Will tinker with the car some more this weekend after dark. It's summertime in Texas folks, ouch!

That distributor came from the salvage yard, and other than a new cap and rotor, I did nothing to the dist itself. Good idea to check out the weights. Will do that!

-Mike
 

81X11

Master Mechanic
Oct 28, 2010
362
1
0
Round Rock Texas
Blake442 said:
Did you use thread sealant on the temp sender and adapter?
It can inhibit its ability to ground through the intake...

Yes I did. I put both the sensor for the gauge and the sensor for the computer in the intake. Will take the sensor for the computer out, and move the gauge sensor to that hole, which is smaller. See if that helps, and then plug the other hole since the computer is going bye-bye.

-Mike
 

DoubleV

Royal Smart Person
Feb 25, 2011
2,153
407
83
Medina Ohio
81X11 said:
That distributor came from the salvage yard, and other than a new cap and rotor, I did nothing to the dist itself.

You're really going to want to recurve it for best performance then. You probably have way too much vacuum advance on it too which can lead to some part throttle pinging.
 

81X11

Master Mechanic
Oct 28, 2010
362
1
0
Round Rock Texas
81X11 said:
Blake442 said:
Did you use thread sealant on the temp sender and adapter?
It can inhibit its ability to ground through the intake...

Yes I did. I put both the sensor for the gauge and the sensor for the computer in the intake. Will take the sensor for the computer out, and move the gauge sensor to that hole, which is smaller. See if that helps, and then plug the other hole since the computer is going bye-bye.

-Mike

I removed the temp sensor for the computer and replaced it with the temp sensor for the dash gauge. Put a plug in the the other now-empty hole. Dash gauge is alive again! Nice!

BUT I could NOT get the Cutlass to run right, got frustrated, and called Neil over at Uncle Neil's Wheels, the shop where I picked up the new Olds 350 last year. He agreed to check it out, and I took it in Friday.

So Neil called me on Saturday and said the distributor I pulled from the salvage yard '77 403 Electra is no good. Weights are frozen and needs new bushings. He said he could rebuild it or I could go get a replacement.

I got on Craigslist and found this ad: http://killeen.craigslist.org/pts/3067712872.html
5N25E65F43G43F33Hcc698c7e799ef9671191.jpg


Called the guy, and he is in Lorena, close to Waco. He's closing down a speed shop and had 200 distributors he's trying to sell. Has them all at $40 each. Brand name is Wiseco from California. Nice guy, he offered to meet me in Temple, which is half-way between Waco and Austin.

Drove up yesterday and met him. Distributor was still new in it's box...no paperwork, but looks good. We'll see! Also went yarding at Belton Wrench-A-Part, but sorry, nothing of note G-wise.

Dropped the new distributor off at Neil's yesterday afternoon. We'll update when I know more!

-Mike
 

81X11

Master Mechanic
Oct 28, 2010
362
1
0
Round Rock Texas
Neil called and said the car runs MUCH better. He's still tinkering with it, and is about to road test it, but he said it starts easy and the idle is much better, the timing is now right and it advances just like it should when revved.

He did say he noticed a coolant leak at the t-state housing...I guess I'm not even a good parts-changer. Doh.

He's still messing with it but it was a good update!!

-Mike
 
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