What brand of headers doe you have. I’ve been looking to replace the stock exhaust manifold but not sure which ones to buy. My car is a stock cutless Supreme 350 rocket with a/c and 350 trans and a peg legger.
also if any one can help having a overheating issue I’ve replaced the thermostat and clutch fan to a flex fan man that thing is loud. Had car running with ac on driving around it would be about 190 and had it parked for about 1/2hr and temp went to 215 all good took a quick spin to cool it down and parked it.and turned it off and it spit out fluid through the over flow. Oh and Rad cap is new too.
Thanks Tommy

 

I moved your post to it's own thread. Your temperature readings are normal.

 

Amen drive a 455 around. Temps will be 250 consistently.

 

thank you

 

yeah man that’s crazy every thing was good till I parked it and it spit antifreeze out the over flow. Next Move I think is to change the cheap radiator it’s a Small 2 core and plastic ends. I’m thinking Of 2 core 1in tube all aluminum. Water pump is good all tight no play in it

 

The reason it puked is probably because it was over filled all the way to the top. There needs to be some head space to allow for coolant expansion when hot.

 

thanks man
I’ll try running the A/C next time out and see what happens car is just about to hit 100,000

 

As far as headers are concerned, don't bother. You'll never be able to detect the HP gain on your butt dyno and IMHO they are a PITA. I have Hedman headers on my 71 98 and they like to blow gaskets. The headers aren't even cheapies!

 

I installed Thornton shorteys on my 70 Cutlass s. I also put glass packs and the 350 now breathes and runs unbelievable.best thing I did.

 

Coolant temps of 250 are NOT normal. The hot light is calibrated to come on around 235ish, no way would driving around with the hot light on be considered acceptable.

All things being equal, a 455 won’t run any warmer than a 350. The key is making “all things equal” meaning a radiator with enough cooling capacity for the engine it’s being asked to cool. You can’t expect a radiator designed for a 350 to cool a 455 under identical conditions.

These cars didn’t overheat when new, properly maintained they shouldn’t now. If they do, it’s time to closely examine the car to see what’s been modified, replaced, hacked up, or removed.

As for the OP, your coolant temperature is pretty normal.

 

hahahah thanks Matt no way I thought 250 was normal I’ll keep a close eye on it maybe do a flush or too and see what comes out. And put an overflow bottle on if that doesn’t quell her. ThenI’ll spend the $$ on a better radiator. And buy a clutch fan hating the flex fan noise. Right now

 

Forgive me if I misconstrued your temp issue. I was under the impression that the engine maintained 190* running and crept up to 215* after it was turned off after 1/2 our of sitting.

 

I’m in the pro header camp, I think they’re totally worth it. Best to match the headers to your engine and overall car package so everything operates in harmony along with a look into your crystal ball. Stock(ish) engine with no future mods, small tube headers (Hooker Comp) would be my choice, like in my kid’s red car (9:1 350, tiny roller cam, 3.08). Modded engines, more aggressive drive lines use medium tube headers (Hooker Super Comps). All out combos, large tubes. Mods in your future or staying stock? Couple headers with a decent exhaust and you’ll feel it. Headers don’t have to be loud but can be depending on exhaust & mufflers.

Buy coated for looks and durability, then hope they don’t need any heavy massaging OR buy painted, fit them, then send them out to get coated.

Now, you may want to get carb dialed in as it could potentially be a little lean. Ignition recurve…..

See how this works?!?

 

thanks for you input on headers good stuff. I had the carb redone already. It the risk of sounding like a dummy what’s ignition recurve? Never heard that term like that. Advance the timing or retard the timing that I know lol

 

https://www.motortrend.com/how-to/ig...-hp-heres-get/

 

Good article and explanation for timing, archived for the tool box.

Thank you Joe

 

I'm dealing with the same issue with my 455 and Summit ceramic coated headers. It's pretty much stock 1970 E heads and shallow dish pistons. I was thinking about getting some exhaust manifolds since the intake is likely the limiting factor.

 

I cannot believe nobody said anything about your flex fan. Those things can come apart and are dangerous. You are better off with a clutch fan. Just be sure the clutch is good. It will be quieter too.

 

Maybe I missed it but I can't find what year the car is.

 

Correct, but its a "Cutless" [sic] Supreme with a 350/350 drivetrain, so it's 1969-1977, and all of those take the same headers.