Why is it hard to start when cold?

I inherited a big 78 Caddy that sat in a car port for six months unused. The engine is a 7 litre with a 4 bbl carb. 106,000 miles

I put in platinum spark plugs (heard mixed reviews about that) recommended by auto zone. Gapped the plugs as suggested.

I installed new plug wires.

A mechanic rebuilt the distributor area for me.

I have to crank the pedel about six-10 times, sometimes wait a minute before she cranks. Once she is warm, she starts right up. Even after 6 hours she will crank instantly. It is when it sits over night it is a pain.

What can I do to fix this?

Thank you!