273/ 2 barrel camshaft options

Bewy said
As the vaaast majority have indicated, myself included, the E-4 cam would be an ideal choice.
Manufacturers produced engines with different ratings; high output, or high performance versions, 2bbl & 4bbl etc. So the E-4 would be a nice step up, with no problems.
Majority of lifter/lobe failures in recent years is from poor quality lifters: wrong radius or poor metallurgy.....or both. So having your factory lifters re-faced will avoid that problem; if your engine builder disagrees, find another engine builder.....
New valve springs are a good idea. If you re-use the existing springs, you might get valve float. The E-4 has about 0.020" more lift so that in itself than the stock 2bbl cam, so that will help ward off valve float if you use the old springs. Really depends on how 'tired' the springs are.
The two centre exh springs are the ones that often lose tension from the heat concentration from the centre exh ports. Any spring that is shorter in free length has lost tension...

Wow! Thank you so much for the detailed explanation, I felt I was losing this battle after some of the feedback I received, in a good way of course! I am not an engine builder but I am mechanical inclined so I appreciate the group’s intentions on doing it right. Thank you so much for explaining the potential of the e4 and the existing components. I plan to discuss these exact details with the machine shop, at their discretion of course, and go from there.

As toolmanMike said, it may be in my best interest to have the critical portions of the engine assembly done by the machine shop. I was just hopeful that would be something my daughters and I could enjoy togeather. But! I am not discouraged by that, there is still PLENTY for us to build together. More to come once I hear from the shop.

Thank you everyone so much for your time and efforts, unless someone else has a 2nd opinion, I will start discussing the Isky cam with the shop and may call isky on where and how to get my lifters refaced.

Oh! I understand getting new springs and a timing set, but with the e4 what about push rods or any other related components? Thanks again!