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'74 455 Rebuild <Ping Dennis Smith>

Well, the weather held and I got the engine and transmission out this weekend. I thought I might be able to get the engine out without removing the headers, but boy was I wrong. I ended up making them more difficult to remove by moving the engine forward with the hoist before I found out there wasn't enough clearance. You gotta be a damn contortionist to get the back center header bolt out. Other than that, things went pretty well. Dennis, check out picture 006. Did your friends '74 engine have this sensor or is that unique to a CA car? I'ts on the back of the drivers side head. Any idea what it does or if it will cause a problem if I don't hook it back up? HD

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(After my last 3 test attempts, I think I got it right this time. Hope these links work!)

Reply to
HoDad
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The sensor on the back of the head is called a "Cold feed sensor" Its part of the Thermal Controlled Spark system(the solenoid above driver's valve cover.) There is also a Temp Override switch on the passenger side head and a relay on the firewall above the distributor. All '73-74 Pontiac V8 engines use this setup.

I'd hook everything up the way its suppose to. All that stuff was missing on my friend's '74 T/A and were putting it back on thanks to a '74 Catalina I found in a junkyard.

All the TCS parts are discontinued from GM and nothing is available aftermarket so DON'T loose anything!

I would replace the headers with a set of D-port Ram Air manifolds. Headers suck!

What heads are on your engine? 4X-1H or 4X-3H heads? You'll find the H code on that part that sticks out on the head just below the front valve cover bolt. I think somebody swapped a set of 4X-3H heads on my friend's engine to bump up the compression. The date codes are off by a year so something looks fishy.

Reply to
Dennis Smith

Dennis, I've got the 4X-1H heads. Correct date codes. Everything is numbers matching and correct on my car. The reason I was asking about the sensors is that I bought a set of 6X-4 heads to bolt on and give me a higher compression ratio. I don't think there is a place on those heads for the sensor, but I'll have to double check. HD

Reply to
HoDad

There should be. That sensor just bolts into one of the accessory bracket bolt holes. The head casting are universal. There is no left or right until the frost plugs are installed. It senses metal temperature so it doesn't go into a water jacket.

Reply to
Dennis Smith

Thanks Dennis. You are absolutely correct. I unscrewed the sensor today, and it is all aluminum so that it can conduct heat easily. Well, today I removed most everything from the engine. Intake, water pump, and heads are all that's left until I get into the guts. I am taking lots of notes and a lot of pictures, too. Thank God for digital cameras! HD

Reply to
HoDad

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