I am removing my 350 and putting in a 400 small block. I know I need a new flywheel and balancer. I have heard you also have to drill the heads. I have AFR aluminum heads. Where and how deep do I drill them and what head gasket do I use? Anything else I need to know? Dan

Here is how to drill the holes http://www.worldcastings.com/tech/RTorquerTech.pdf
just use a gasket to punch mark the spots, and one hole goes straight in and the other and an angle.
Other than the correct flexplate and balancer, that is all you need, other than a good set of tires http://www.nastyz28.com/ubb/wink.gif

Thanks for the link. When the holes are drilled, are you intersecting a water passage?

Yes, that is the whole idea, to intersect a water passage. Actually here is what AFR says to do with their heads, just in case their castings are different:

Steam holes are recommended for all 400 block applications. Use a 400 Gasket as a template and drill the three holes, nearest the spark plug side of the head, straight down. The other three which are very near the head bolt holes should be drilled at a 30° angle away from the bolt hole. The center hole will intersect water about 1" down and the two outboard holes to a depth of 2 1/4". Use 1/8 drill.

Great Info ! I didnt want to drill too deep. Thanks for your help. Dan

Anytime http://www.nastyz28.com/ubb/wink.gif Us 400 people gotta stick together. They can be tricky!

I had the local machine shop drill steam holes in my 400 for about $20. I wouldn't trust my hands on a $1500 pair of heads. Rob (78LT) on the other hand does that for a living! lol

I thought LT worked in a heat-treat shop?

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'Silver Bullet' 1977 Z-28 413" SB
11.73 @ 115.10 on drag radials
Old Vortec combo:
12.15 @ 110.52