318 cam change

Steady driver said
Vin code says 273 This evening I lined up the timing cogs 6 top 12 bottom with front drivers piston at tdc but the rotor arm is at number three piston I think , anyway I removed the cam and the heads look like they have been skimed I noticed silver steel underside . Question. The rubbers inside the springs are nice condition but some are up some are down is normal ? ( I have not removed the heads) and stil not checked diff ratio the front is on axle stands . Question 2 I offered the old iron inlet up to a spare engine a old friend gave me (318) but the bolts are straight up type When did they change ? Also I still ain't checked the engine code. Fore a date yet sorry krazy cuda .

The rubbers on the springs that you refer to are called valve seals. Some of the factory seals will be up and some down. My head guy doesn't like that style and goes with the more positive locating seals that grab onto the valve guide. Sometimes the head needs to be machined for them to fit properly, but they last longer and work better. Here are some pictures of them:

View attachment Valve seal D01 B.jpg

View attachment Valve seal D02 B.jpg

View attachment Valve seal D04 B.jpg

View attachment Valve seal D05 B.jpg

Question 2: The straight up type intake manifold bolts (you call it inlet) that I think you are referring to are for the "magnum" series engine that started in 1992 and newer.

From 1964 to 1991 the small block is called the "LA" style small block.

So I saw that you said that your car was originally a 273 from the factory. I would check some numbers on the block to find out what vintage 318 it is. A quick check of the number on the front of the block just below the head may give you a clue. You may have to do some scraping and cleaning to see it, and sometimes they are not stamped deep and hard to read, but worth a shot until you can crawl under it from below and check the casting date on the side of the block...