Car: 74 350

I'm sure it has been covered many times before, but didn't find specifics in the search I did. We removed the stock distributor, and dropped in an HEI in the same exact position. The timing wasn't working in the stock distributor that had a pertronix kit which is what prompted the swap. After install we realize it isn't going to work out so well in the regular position. The vac advance on the side of the dizzy is right at the dipstick tube, and the part where the wires plug into the HEI, hits the air cleaner.

My fathers friend dropped the HEI in, and it ran... but didn't have the time to make it right. That's where I come in... I want to index the entire distributor one position to make the electric connector point to passenger fender, and get the vac advance port out of the trans dipstick. Car runs fine right now, but want to make sure I take the proper steps to make sure it stays that way

Besides watching the dizzy dropped in yesterday, i've never done one before, which is why I am looking for guidance. I've read to pull the plug & dizzy (since position wont matter right as I am looking to change #1), bring engine to TDC, and back it off a few degrees. This is where I get confused in a hurry. One diy says it isn't necessary, another says 6-8 degrees, and another says 6-12 degrees. I can't see the tag that well on the balancer, so I will have to clean that up. What is normally recommended for corvettes? (like 75 when they did have HEI).

After I do that, I guess I drop the dizzy in place where i'd like it... and I take it that rotor position is what I need to note? Would I have it point to where the #2 stud is normally then? I'm assuming I have to swap my wires around a rotation, but once again this is where I start getting lost. Can anyone guide me in the right direction?

Thanks in advance!

 

just move all the wires over 1 notch, and rotate the distributor housing the same amount as the wires.

 

Is it really that simple? I'm not doubting you, I am just laughing at myself for how over complicating I was making things. I just grabbed the old dizzy we removed and tired what you proposed in my hand.. and your are 100% correct. Now I just need to get a hold of a timing light to make the final adjustment. What do you guys time your cars at? We had it cranked up last night and got hard to start. We settled at 15-17 degrees.

Thank you!!!!

 

69Vett is right.

one wire notch on V8 dist = 1/8 of 360 degrees = 45 degrees rotation of dist base ... swap wires one notch & turn base 45 degrees.

 

there is also an exact measurement for how far the distributor will move forward as the gears slip together.....so mark where your rotor is pointing slowly raise the distributor and when it comes free mark where the rotor is pointing. this distance will always be the same.....

assuming you are at TDC compression stroke... just make the spark plug wires line up where you want it to be....mark the #1 spark plug tower base on the distributor base and then measure backwards on the face of the distributor base and mark the line (for the distance the distributor travels) and drop the distributor in and it will rotate pointing to that spot.

 

I appreciate the help guys! I picked my own reference point, and did the 1/8 rotation. I then swapped the wires back one like mentioned. Can't believe it was that simple. After I got everything in place, I went to start the car. To my surprise, it worked . Now the trans dipstick is clear, the hei wire port doesn't obstruct the air cleaner assembly, and she is all back together. I am sure it is in the ball park, but still need to get a hold of a light to see where the timing is at.

The only downfall is now the vac advance port is in the way of the spark plug wire bracket that mounts off the manifold. Not a big deal imho, since the top piece can't be used anyway because of the distributor size. Was there a shield on 75's?

 

yes ... chrome box & lid ... most of the suppliers offer them

If your new hei has a mechanical tach cable for 74 mech tach ... you may have to wrangle the mech tach cable to clear the box. 75 has elec tach.

 

Thanks again. The HEI we put in does not have a mechanical tach drive due to cost and other issues. For now it does the trick, but will be swapped out eventually with one that has the tach drive.

I did get a hold of a light and set the timing. Too bad it is raining...

 

When it stops raining, you can use this to set the timing:

http://forums.corvetteforum.com/c3-t...long-post.html

 

Seems to me it would have been simpler and cheaper to put back the stock points and condenser in the OEM distributor, or install another pertronics type widget..........

 

Just a quick post regarding Pertronix. I am considering an HEI ignition to upgrade the stock contact breaker points on my '69 350/350 just purchased. During the search to buy a car I drove an immaculate '70 with a 454, completely stock except for a Pertronix Ignitor III drawing from their Flamethrower coil. The owner said the upgrade produced improved engine response especially at high RPM, and instant starts. Just my two cents. I'm leaning towards buying the same.

 

your going on the word of someone who said ...blah blah, "owner said"
yes it may have improved performance, over his poorly incorrectly adjusted point-setup.
any new Ignition most likely would have provided the same Improved results.
Imagine Driving thru Egypt.... one day and your igintion Dies,
Not going to have Pertronix at the local Auto parts store.
If your gonna upgrade, I would suggest go to a standard good HEI ignition.
Nothing really wrong with points on a standard street motor.

 

A pertronix or similar points replacement unit is NOT the same as an HEI system. That aside, neither will inherently give a performance boost over a stock points and coils system.

As stated many times before- a spark is a spark is a spark.

 

I innacurately quoted the guy who told me about his Pertronix system. What he said was the engine seemed to run smoother and not with better performance. I would'nt think installing it would produce more performance, but I would think that the more accurate spark timing and more spark could make it smoother. It's anecdotal but I listen to that stuff when I trust the source and in this case I did.