advance kit
Your timing comes from 3 sources, initial set at idle with a timing light , vacume from the engine and centrifigal from the advance system in the distributor.
If you really want to nail down the timing on your car, this is what i'd do.
1st) i'd go get a advance curve kit that fits your distributor (moroso or mr gasket , or accel is where i'd look ) since the new cam will have different advance needs than the cam you removed.
2nd) I'd get a timing tape that fits the harmonic balancers diameter of your engine ( mr gasket has them ) , clean your balancer up very good then put it on
3rd ) decide if you want to keep the vacume advance feature in your distributor , fuel mileage might suffer without it , but it will be easier to set the distributor up without it. Your call. But i'd buy an adjustable vacume advance canister for your distributor if you want to make the oil cartel nervous and install it while your putting in the advance curve kit
4 ) re-install your self made hi-po distributor
Most advance curve kits come with a bushing to limit total centrifigal advance to 20 degrees. Check into this , this might be a good time to change distributors. IMO , i like the early chevy point distributor because you can convert it to electronics or use the points with an MSD box and I like the centrifigal advance system better. Accel makes a great kit for this distributor to convert to dual points that comes with a vacume advance lock out bracket and it has the bushing to lock the centrifigal advance to 20 degrees if i'm not mistaken , and also includes an advance kit as well. If you want to use points with the MSD , remove one set of points and the condensor and adjust the set of points just so they open and close and your done there. The MSD box will only send 5 volts to the points at a low current so a set of points will last a long time. I ran this set up for years and it was mis-fire free to 7200 where I wound my engine to. An MSD tech at a national event turned me on to this set up and it worked great for me. I have found that even this combo provides better starting than an electronic trigger from a HEI but thats me.
Might seem old fashioned but I like stuff that works.
With the car at idle , set it for 14 degrees at idle , with the vacume advance disconnected , watch the timing mark with the light and raise RPM at see where the timing tape is now telling you your timing is advancing to. Hopefully it should be close to 34 total with the advance kit installed.
This is a good time to decide if you want to continue to use the vacume advance. Since the new cam will defunct the stock settings, IMO , i'd connect it to manifold vacume instead of "ported " and set the new adjustable canister to add about 10 degrees timing checking what its doing with a timing light on the timing tape. Drive the car like this , do a full power run and listen for detonation. If you hear it , back the timing down 2 degrees and try again, back it down 2 more degrees until detonation goes away. If you want to go down a spring size on the centrifigal advance, listen again for detonation and adjust from there. A chassis dyno would be a great help but testing at a track is prolly the best place to set centrifigal advance.
If you decided to keep the vacume advance , do some driving up hills and listen for detonation using as smooth of throttle aplication as possible so you can ensure its the vacume advance thats doing anything with the timing at this point. You might slow the centrifigal advance down with a heavier spring and keep all the vacume advance as u can but you'd have to do some back to back testing to decide which way was working best. You might instal a vacume gage to tell how well your engine is staying at a steady speed without applying more throttle while increasing engine load going up inclines. This will give a more precise indication of what you just changed is doing. You could go back to the " ported " vacume source and see which way your engine likes best, but i bet it will like manifold vacume better
You could disconnect the vacume advance and see if it is helping your fuel mileage and lock it out if it isn't. This will give you certain numbers what your timing is doing but might be more intended if you step up in performance later on
I hope this helps you.