I'm going to be purchasing a 427 short block next week that has never been run. It has Keith Black silvolite pistons in it and from what I've been told it's a stroked motor (as opposed to bore) and is .30 over. I have the opportunity to purchase some nice oval-port 454 heads for dirt cheap and the million-dollar question is......will they work on this 427? I'm kindof new to the whole big block scene as I'm traditionally a small block/ camaro kindof guy so please don't laugh too hard at my post..Thanks!!!

shouldn't have any problems it's just like SB's just a BIGGER block LOL,, the only thing you may have to check like any motor is piston/valve clearance etc. but it should all work... what heads you getting.. 781's or 049's?? those are great heads...

One point is to get the actual bore and stroke measurements b/c a "stroked" 427 just may be regular 454!! And not a 489" motor...

pdq67

There is no such thing as a stupid question, only stupid people. With that said, I just got done doing this research also. Depending on your pistons, you may need open or closed chambered heads, If you have closed chamber heads, and open chamber domed pistons, there will may be interference problems. Vise - versa you probably will not make as much power as you could due to low compression. I've always been a small block guy myself and am just getting into the big stuff. It should be fun!

Any time you use a head you are not sure of with a piston you are not sure of, I highly recommend checking the real compression ration. Bolt the head on with a gasket the same thickness you plan to use. Tilt the engine on the stand until the #1 sparkplug hole is straight up. Turn the engine to TDC #1. Measure the amount of trans fluid that you can pour into the cylinder. You can get cheap plastic syringes at the Veterinarian supply that work great for this. Now move the engine to BDC #1 and fill the cylinder again. Note the total amount now in the cylinder. Divide the first number into the second and you will have the true compression ratio. You can also get the second number by just adding the displacement of one cylinder (in CC) to the volume of the TDC volume. You can vary the thickness and adjust the compression ration somewhat in either direction. This is the most accurate way to allow for the piston dome and chamber volume to compute CR.

Before you put the heads on use a piston stop to find your TDC and make sure all your timing marks are correct this will save you tons of grief if things are not where the need to be when trying to set up your timing. Don't trust the balancer to be marked correctly once you have the pointer and balancer set to TDC put a timing tape on the balancer that's the correct size for the balancer diameter. It also wouldn’t hurt to recheck the cam timing before you put the engine together it’s nice to know all that stuff is right if you have any problems later you can at least know
it’s not any of these.

"Any question you don't know the answer to is not stupid" my grandpa Skiman

Thanks guys. You all have been really good to me and I appreciate it. I was going to do the syringe/plexiglass cc test on the heads and since I'm going to tear the short block apart I figured I could lift a model number off the pistons and get an idea of the supposed CR. I was just concerned with compatability. That they would bolt on okay and all the water passages would be free and clear. I will also be doing a Piston to valve clearance anyway just to be certain. I know my way around buliding my own small blocks pretty well and wanted the sense of accomplishment with building this 427 myself as well. I hope the SB and BB don't differ too much. I'm going to have a shop rebuild the heads and also balance my rotating assembly but I want to actually put it together so you may get a few more basic questions from me but I just want to be safe. Thanks again for all your help!!!
Hey, i'm painting the frame right now and it's almost time to bolt everything back together!

Asking a supid question is better than fixing a supid mistake !! graemlins/clonk.gif !!

A wise man once told me " The only stupid question is the one the wasn't asked"

It sounds like your engine is both bored and stroked!

I just love what Mike has in his sig!!!

""Life is tough.,, Life is even tougher if you're stupid."

-----John Wayne----- "

Yes, the only stupid question is the one NOT asked!!

AND if you ask a question and get onna them "big headed" answers, the person answering is usually the stupid one with the "big head", imho!!!

pdq67