Setting up valvetrain with new heads

[dubs chops]

Lord have mercy I need help. lol

long story short"er"

I have a 383 that has flat top pistons in it with 906 heads. I bought some ported Eddy heards that were decked .010

I was going to re-use my Rockers, pushrods,lifters,cam
the problem came when I wanted to clay my head for valve clearence. I needed a couple of solid lifters to use for the test instead of my Hyd ones. I had to take them apart and shim them to get them to the same resting height as my Hyd lifters for the clay test. How would one normally have to do this since you can't adjust the stock rockers?

Going forward I think my old pushrods are too long. when I bolted up the old rockers on the new heads with my makeshift lifters there was ZERO play in the rocker arm. I am pretty sure even slightly compressed wich ruins the results of my clay test.

So whats the proper way to go about this whole process? Thanks in advance for any help.

BW

 

[moper]

I use checking springs on the valves and solid lifters. If your engine wasn't blueprinted you should probably do the four corner cylinders at least. Anyone with a pre'67 273 they're tossing has a full set you can get cheap. ALso - use a pushrod length checker to figure out the right preload with your setup and either find a catalog number that works or order custom pushrods.

 

[dubs chops]

What should the preload be? since my pushrods seem really close I am debating just buying adjustable roller rockers instead of custom pushrods.

thoughts?

 

[miller]

Or, go with thicker head gaskets. All about options.

 

[moper]

Preload depends on the cam and lifters. If it's a fast rate modern profile you have to know what lifters are on it. Most can be run with stock lifters with anti-pump-up lifters as an option, some must run the anti-pump-up. Stock lifters I like to set at .050-.060" preload. Anti-pump-up I set at .010-.015". Rockers should not be used to adjust pushrod length. Exposing too many threads of the adjuster below the rocker body gives the pushrod leverage that can snap the adjuster screw or break the rocker. That's why you use a checking tool and set the adjuster screw to be 1 thread or so showing below the rocker, at the correct lash or preload setting. As is noted - the head gasket can also effect pushrod length. Going from iron to aluminum usually (or should) include a switch to the correct head gaskets (those with a pre-flattened fire ring) so that also will change the pushrod length variable.
Pushrods are always the dead last part I order when I build an engine. It's much easier to assemble the long block and measure to account for all the variables that can effect the length. Then it's a phone call and 2-3 days and they're there.

 

[dubs chops]

OK so I am using non adjustable stamped rockers for now. I think they are close enough to use,. I have a mopar purple (That's all I know) and Hydraulic lifters. I don't know if they are anti pump up or not. I am thinking at the current height I am going to have about .02-.04 preload. if that's the case I think I am good to re-use my pushrods correct?

 

[miller]

Probably. Be sure to use the same thickness head gaskets. At least check the tappet pre-load. .020 - .040 would be minimum, since all your parts seem stock. If you have to change your tappets, could be looking at custom length pushrods. (Tappets are not made like they used to be.)
Only if your tappets are in real good shape, at the bottom running surface, if needed, they can be busted down for cleaning. Though you might as well know, each tappet MUST go back on the same cam lobe (wear pattern), and you do not swap parts, from one tappet, to the next. (Old school stuff)

 

[miller]

I bought some ported Eddy heards that were decked .010

Hmm...just re-read that. Add .010 to the thickness of your head gaskets. Pull off .020, put on .030.