Im working on my friends 67' 327 Camaro and we're gonna be changing the oil pump on it since the engine is out. Were thinking about changine the cam as well so i guess changing the springs will be necessary as well, so other things will be needed. Do you think the valves will be needed to be changed as well? Well, the oil pump pushrod seems to the immediate hurdle so we'll be tackling that first, or do you guys suggest us go with a hardened aftermarket push-rod?

 

You mean the oil pump drive shaft? It comes right out when you remove the oil pump. HD shaft is cheap insurance, especially since it comes with a steel sleeve vs the plastic one used on stock shafts. But I've never seen or heard of a stock sbc shaft breaking when used in mild SBCs, so it's a piece of mind thing. It's not like fords where shaft failure is common. I've seen more than one of those twisted up like a licorice stick.

How many miles on the heads? Do a compression test or leak down test, and if it's ok, valves should not require replacement. Definitely replace the springs.

 

As mentioned above, it comes out with the oil pump. The factory style shaft uses a plastic retainer that snaps onto the pump. The plastic retainer can be easily broken when removing the shaft from the pump. That's why when you buy a new oil pump, it comes with a new plastic retainer.

An aftermarket drive shaft has a built in metal retainer that slides over the slot in the oil pump shaft. Even better is a Melling Select oil pump. It uses a hex drive shaft which comes with the pump. The Select series of pumps still use the better old castings and have a better design.

Whenever changing a cam, new springs should be installed that match the cam. Have the heads set up to match the cam's lift also.

Changing the valves depends on how old they are. Chances are if they're original, they're all going to be worn out. Price out a new set of complete aftermarket heads before investing in rebuilding the heads unless you're trying to keep a matching number car. The price of new heads complete with valves and springs can be cheaper than rebuilding old heads and will be much better castings.

 

If the plastic sleeve fails, the oil pump shaft will rattle around and make a heck of a noise. the aftermarket shaft with the metal cap is cheap. Have always upgraded to it on all big and small blocks...

As stated above, Depending on the projects goals and the engines end usage, upgrading the heads to different castings that have been fully moded may be cheaper...

If you need to keep it "original" then it can get fairly expensive.

I recommend hardend guides and stainless valves for both big and small block checys...

If you have to replace the valves, it can be a good time step up to a larger size valve..the intakes can be opened up to except the 2.02's..fairly inexpensively...Most shops can simply grind them out to fit the 2.02 and undercut the pocket..most times this will bring the valve back to the correct installed height.

the exhausts are a little more complicated..

the exhaust seats should be replace with hardened seat inserts (the purpose of lead in old gas was to lubricate the seat and help slow down exhaust seat wear, when unleaded came out, the manufacturer started laser hardening the seats in newer casting to increase seat longivity.) (the absence of lead doesn't seem to have much efffect on the intakes....)

so to increase longivity on rebuilds one should install hardened seats in the exhausts, especially if you run stainless valves....

If your going to replace the seats and valves then upgrade to 1.6 exhaust valves as well...

I routinely recommended this to my performance customers on both small and big block chevys.

again this all depends on you project goals and what you are going to be using the engine for...

G