'70 318 BBD falls flat under load

just to throw it out there but compound problems are the biggest head scratchers if it were me i would check the timing........it might be coincedence when things happen but like i said just to throw it out there.....

i would try advancing the timing to see if it helps any .....if it gets stronger the more you advance, that means the chain stretched or skipped ....

im just throwing it out there bcoz i had a timing problem with same symptoms ....and it might just be coincendental that you changed the carb at this time.

just to rule things out bcoz compound problems are noodle twisters