Pete,
Ditto that ground strap. I ran a ground strap from the bracket that the forward brace roll bar bolts to, over to the bottom starter bolt. I used a ground strap from an MGB that is used for the same purpose. You can buy them new from British Victoria.
I too have not had a "hot crank" problem after I installed the strap.
Also, it may not hurt to have a look at all the connections to see that they are clean (no paint or corrosion) and tight.
Keith