distrib cap. Small caps are more prone to cross fire. reason is contacts are closer together. large cap contact are farther apart. path of least resistance situation. So as you drive a gas is built up within distrib cap. which promotes a path of least resistance. crossfires and fires the before or after cylinder which usually means a lean cylinder which usually makes heat in cylinder which takes away engines ability to cool. MSD makes a distrib cap and phaseable rotor. rotor allows you to pinpoint your contact to the cap contact. but everytime you make a adjustment to timing you need to confirm rotor to contact. once its all tuned in your good. also helps with coil saturation time in high rpm application. the bigger the GAP between ROTOR and distrib CAP less power to sparkplug. Takes more energy to jump the gap. to those who have tuned up a engine like this know the difference. to those who have not debate it. used to grind my rotor for more accurate contact and cross fire protection. if running a vacume style distrib cap you might be surprised on your spark jump in cap. Get a spare cap and grind a hole and use a timing light to watch while running at house. simple little tuning process but effective. learned this about 16 yrs ago back in the racing days! mud racing and high rpm and then crank triggers solved the high rpm problems. some caps come with a vent and some don't. Usually have to confirm! scary simple!

 

electric fans? If you have no way to confirm cfm's a little test. set fan on the ground and hook up a battery and fan should almost fly off the ground. if it just sets their and moves a little thats not enough. pusher fans like hayden just kinda sit their. Poor boy setup is a factory HO fans on the lincoln 302's work well. 2 speed fans with single fan. works really well, shroud built into factroy setup and mount to radiator. need to break out tape measure and confirm and some fabrication required. salvage yard shopping, if elec motor goes out order one at your local auto parts store. Or look for a fan with 5000cfm and will be good. I run big blocks to 500ish hrspwr big trucks and all these factors come into play bigtime. sittting in traffic hard on coolant systems in texas! Next is confirm your cores on radiator, 2 core 3 core 4 core. radiator has to hold coolant long enough to drop temps. also like mentioned spring internal on lower suction hose to pump. during higher rpms hose could collapse and restrict flow to engine with coolant. i have personally had this happen and it does create odd heating situaitons. scratched my head on this for a week or too! couldn't see the forest cause all the trees in the way! Ha! Ha! on me! sometimes the simple crap just kicks my azz! good luck!

 

@ Wyoming : wow, this is a lot of input !

I´m definately considering a wider distributor cap. Would require some modifications on the connectors but OK. Seems that MSD offers a replacement set for a Ford Duraspark but no phaseable function (only for Chebby). Good idea also with the spare cap, I´ll try this !

 

Wyoming, how do I find out my radiator has 2 or more cores, please ?
Lower and upper radiator hose are with internal spring ...

Thank you for sharing your experience, gave me something to think about.