[HO455]

I'm sorry your friend passed away.
As to your engine delema I recommend talking to local racers about someone in your area who is good at tuning carbureted engines. As Skidmore suggested dyno time is a good way to go however it is expensive. And nowdays many dyno shops are not experienced with analog engines like yours. If someone immediately starts saying you need to change part XXX then go somewhere else. They are likely looking to up your bill because they are underhanded or they don't really know what they are doing and are hoping for the best. Ask them how changing this part will change the engine for the better. If they truly know what they are doing they wil be able to explain it so you can understand.
Once all the avenues of tuning are explored then you can decide what parts might be changed to meet your goals.
Try and remember the conversations you and your friend had about what you wanted from the engine. Maybe write them down. Your friend made choices about components based on those conversations and it may help whomever you find to help get the performance you desire.
There are many ways to build an engine and 10 times as many opinions about those. There doesn't seem to be anything particularly wrong with your current combination so hopefully you can find something as easy as recurving the distributor will wake the engine up.
As this goes forward you may have to pull the water pump off to verify the cam timing. Also be prepared to have to pull a cylinder head as any speculation on compression ratio is a waste of time until you know what the deck height is.
These are the bad case scenarios. Worst case would be something like a cam lobe gone flat or rings that never broke in properly.
Good luck and please post your findings.