If that shield doesn't work (been known to happen!) here's a couple of other solutions.
Do 'The Big 3'.
Check the battery condition & the connections. Especially the grounds.
Put a bit of high-temp grease on the solenoid plunger.
Wrap your headers. But, than can cause problems over long term. Be prepared to be welding up cracks in the headers. Headers have also been known to collapse, develop flat spots, or cracks over time, when wrapped. Either that, or replace them every 5 years or so. (If wrapped)
Swap to a high-torque mini starter. ($110?)
Change the 14ga. wire from the stock GM battery cable terminal to the starter switch terminal with at least 12ga. 10ga would be better.
A Ford starter relay. ($25.00!) Remove and reroute all the battery wiring that was on the GM starter to the Ford relay including the start wire, and run a starter cable to the GM solenoid and make a jumper from the heavy duty pole to the start pole on the solenoid.
Fords, Lincolns, and Mercurys of the early '70's with 429's and 460's used a GM starter and wired it up the same way from the factory. I like to use the stamped jumper that was stock on the Ford unit because it fits and looks professional.
The eddy current causes a field around the solenoid plunger and can cause it to swell and draw heavy current when hot. By removing all electrical connections to the solenoid except when cranking, the plunger would not swell enough to drag or bind and cause the slow/no crank.
The use of a Ron Francis hot start kit HR-67 eliminates the problem. The best way to make sure before you buy it is see if the engine will crank with a screwdriver across the battery and crank terminals. That is the big terminal in the middle and the smaller one closest to the block. If it cranks, then this system will solve your problem. Lots of people with headers install the HR-67 from the beginning to make sure they never have the problem. Order catalog at
www.ronfrancis.com (
http://www.ronfrancis.com).
Hope this helps.
