Hey everyone. Thanks again for all the help on the oil pan thread.
I have a chance to buy an older set of Indy 426 1RA, they have a 2.380 valve and the 1.940, does anyone know if they will fit with a 4.280 bore? I have CP pistons that are 13.08:1 compression, they have an intake valve relief which at the widest part of it is 2.450 and tapers down to a 2.250 and no valve relief on the exhaust side. I also have no info on the pistons besides the brand and that there a 13:1 piston. Thanks.

You will probably have to notch the cylinder a little for the big intake valve but it's not hard. I can send you a link to the video if you need it.

Thanks for the reply, the block already has a little notch out of it right now, it’s a world block so they must have done it when the machining was done. Send the link please.

I've rented and used the Isky tools for notching both pistons and cylinder wall bores
Not real precise but I did get more than enough clearances with those tools and a good 1/2 drill motor
I ended up buying all those tools I needed on the second engine that I needed them for

The part you want is near the end https://www.youtube.com/watch?v=Ewcj796lTKw

Thanks. I’ve been watching all your videos on building a hemi. Thanks for making them.

You're welcome and thanks for watching. I'm trying to show little things that others don't cover.

Any links to the videos

Here you go

https://www.youtube.com/watch?v=iKkjpiraZnw

So it’s safe to say that anything under a 4.500 bore you won’t be able to use the 2.400 or the edelbrock 2.320 intake valve unless you notch the top of the cylinder? Has anyone tried the Indy 426 1RA with the 2.400 valve on any bore size under 4.500 to see if the work? Thanks for the help.

Yes. I don't know what size you mean? 4.375? I don't know. I guess it would also depend on the head gasket thickness. It's easier to notch the block.

What block are you using now?
Can you set a head on it with light checking valve springs to check the current clearances? If so do that next

My bore is 4.280, it’s a world iron block, it is notched at the top already but not sure if it’s enough. I don’t have the Indy heads yet. I do have a buddy with the stage 5 millennium heads and those 2.400 intake valves hit either the block or the piston. I did try it with checker springs. The Indy heads I’m thinking of come with Norris rocker arms, how good are those rockers? Thanks

The Norris exhaust rockers I used on a motor years ago were okay for a street and strip motor, way better than the stock ductile iron rockers

I do love the thought of Millennium heads but I think that's a bit much. Custom intake etc. (And then how big is your selection of intake manifolds?) The problem with using checker springs is yes, it cleared. But what if it's only by .001"? The checker springs won't tell you. Then what happens when it's running? Just notch the block to spec and quit thinking about it. It's fast, easy and if you want to go back to 2.25" intake valves it doesn't hurt anything. 59 years ago the Chrysler engineers gave you room to work with there for this very reason. That's why they gave you that recess in the head gasket. Give them the respect they deserve.

The millennium heads have an adapter plate that comes with them. My buddy was using an Indy tunnel ram intake for it and 1 1150 dominators. Apparently it was making 920hp from a 477 engine. Ya your right, just gotta get the heads to make sure it’ll clear, and if it doesn’t then so be it, notch it more. This might be a stupid question, would you take all the pistons out to do it? Or just mask it it up? Thanks.

Of course the proper way would be to tear it down, but by turning the cylinders horizontal on the engine stand with careful masking you could probably do it. I would just tear it down because I'm not in a hurry.