Introduction and hot starter problem

[Kenuck]

Just thought I should re-introduce myself before asking for some advice. I have not been on the board for a couple of years now. I have a 47 Merc truck that I completed back then and while working on it I received much advise and assistance from this board. Since then I have enjoyed driving the truck and other activities have taken up my time. I am now planning to get back on the tech board and seek some advise, so just thought I'd let you know who I am. It's good to see your still here and going strong.

Now for my problem.
I have a problem with the starter on my 47 merc truck. It only happens when the engine is warm, and not all the time. It is the worst when I shut down breifly (i.e. at a gas station to refuel) The starter engages so it's not the solenoid - but cranks very slow or not at all. Sometimes the starter will crank slow for a couple of turns then start spinning normal, other times I need to let it sit for a few minutes before it will work.
I have checked and rechecked the battery and ground connections, upgraded the wiring to heavy gauge (the battery is located towards the rear so the cable is long), even changed batteries. The voltage drop between solenoid and ground is 9.3 volts when starter is cold and when hot, but when the problem occurs the cable between solenoid and starter gets very hot.
For a while I thought the timing was too far advanced and actually working against the starter, but retarding doesn't help.
I have finally concluded it must be the starter - I am running a 351W with block hugger headers and the clearance between the header flange and front of starter case is almost zero, so I suspect the heat is causing the problem.
My question is - do you think I am right with this conclusion, and if I replace the starter will the problem just reappear?
Does someone make a short case starter for this application?

Thanks for reading this and any advise would be appreciated.

[40]

Welcome back! A mini high-torque starter should solve your problem if someone makes one for your application.A heat shield will also help.

[Bib_Overalls]

McLeod and CSI make mini starters for the 351.  http://www.summitracing.com  sells them for a lot less than going direct.

Search part numbers MCL-810155 and CSI-105.