454 troubles...
I've owned 4 454 motors,all of them smoked a bit,but used only a quart of oil every 700-1500 miles,slightly more in hot weather--all had at least 100,000 miles on them...
One 74 motor I had out of a Chevelle had noisy wrist pins--you'd hear them most when driving about 35 mph--standing still,you could not hear them much for some reason..a few guys at local machine shops sat 90% of BBC motors have loose wrist pins at rebuild time--many have cracked piston skirts too..2 of my motors did,and I didn't know until I took the oilpan off of 1 motor to replace it(rotted thru!),and found it in the oilpan!...the other I only heard about from the guy I sold it too!--luckily he's a friend of mine,and planned to rebuild it completely anyhow,so it was no big deal..
Your "ticking" could be any of theese things and more,could be valve train,bad cam lobe,timing chain loose,even the fuel pump or its pushrod,etc..it will take some probing with a stethascope or peice of hose in your ear to try and narrow down where its coming from...removing plug wires while its running might help diagnose the noise too(use well insulated pliers or you'll get zapped!)..wrist pins usually get louder when the plug wires on the cylinder with the loose one is removed...bearing knocks will get quieter or dissapear when that cylinder is disabled..
Compression should be at least 120lbs in every cylinder--but its more important that they are all close to each other more than the exact pressure..one of my motors only had 100-120 lbs compression,but it also was the one that ran the best!--a leakdown test gives more accurate diagnosis than a compression test.. I'd say its due for a complete going thru with the amount of mileage and its unfortunate overheating dilema...but it will probably limp along the way it is for a long time too...but you wont be doing it any good by running it this way for long...
