i ran big valve heads on 3.5 in mk2 escort many years ago they were actually equvilant to 3.9heads. so i cannot see why your 4ltr heads wont work. if it was me i would ditch the electrics and run carbs. im big fan of twin su.s or whak in a lovely 4 barrel holley for wicked accerlaration of the...
you need a very strong battery for a range. dont expect it to be less than around £70 at a guess. there is a battery that recommended for a range but i cannot remeber the number for it. try a search on this forum it only listed few weeks ago im sure.
your battery is completey knackered then if it wont take a jump just becos it 2wk old dont mean it good.{ i brought 1 once took it back same day as it was well xucked}. or ya leads are not sitted properly, or live feed to starter needs attention.
why $ and not £ ? skimming of heads is around £60 pair it simple job and dont take long. as for valve stems then probably another £50. so around £125 or so about right depending on the garage.
it might of been head gasket but you already done that so that why you have the exhaust steam. you still have coolant problems i beleive, do you have another rad you can swap ova. it worth a try. also i pmd ya a message it only a thought worth looking at.
if not as above then you have to get codes read and reset. as with p38 we never disconect the battery, if battery dead then we run jump leads across while battery bein swapped to keep the currant flowing in the car. this stops the faults.
i dont think it the block gav, are you sure all the water ways are clear and you get a good flow through one end out the other if bottom hose of the rad is dissconnectd and stat is out?
just a thort gav but when you did run up the engine did you have plenty of antifreeze? if not then the coolant be frozen and you be overheating all over again mega quick.adam