BPE HEI Distributor

You killed me with the accronyms
BPE Blueprint engines or Bouchillon performance electronic?

etc

anyway if it has initial of 16 BTDC and starts ok when hot with the vacuum advance connected to manifold rather than ported vacuum
and the vacuum gauge jumps about at idle
i'd suggest you must be getting some advance off the vacuum can when cranking and just starting. i.e it will stomach a bit more initial and you can put the vacuum pipe back on ported

if you remove vacuum advance from the equation and it then needs more initail to run ok in the low rpm range, that follows on from above

but then kicks back when hot on starting !!!!

that seems to idicate that it needs more initial to start and run cleanly but not so much as to casue a starting issue at a time when its all warmed up

unless starting issue when hot are heat soak into the starter and not an initial timing induced kick-back

its quite a big motor i wonder if you just need the advance to come in quicker. to smooth the transition from idle to mid rpm

if there are facilities in that dizzy to restrict advance and change springs etc you can go with less spring to bring advance in quicker
and its worth seeing if you really need 34 total, wedge heads might, but open chambers on a high compression motor, might not
depends on cam carb and balanced distribution across cylinders

if it uses an HEI module for spark and dwell it will be a 4 pin version

if you switch to a A 5 pin module from an 1980 Oldsmobile 260
you get, as it says, a 5th pin which is handy
that 5th pin when grounded retards the igntion timing by 10 degrees

would allow you to connect pin 5 to a switch to gound it out when starting or when having a starting problem

i.e have 6,7 8,..... BTDC for start
flip switch off and go to whatever initial timeing gives you the clean tailpipe at idle and gives you the "on the peddle" kick in the pants thats missing

you can then tune the vacuum advance on the ported vacuum port. to do what it was inttended to do rather than usiing it as an assistant with starting...

i have only ever had a manual 4 speed car so the whole "use the vacuum can on manifold vacuum" situation that you can do with a highlt tuned v8 on an auto always feels wrong to me, but thats just my view. pleanty have great success really seems to depend on Cam

i may have mis interprested what you meant,
i'm in a different time zone and country which means i see stuff that is not answred before some of the USA does

I have motor with half the capacity of yours
mine runs 15 initial and 28 total i can't start it at 17 initial without risk of smahing my starter 16 is marginal for me.

Your question had no answer, what i have said may or may not be on the right track but those 5 pin modules are quite cool :)


Dave