Milling my block .055

[manofmerc]

I have a nice c6me block .This is a .050 over 352 using std. 390 pistons cast flat top with the four valve reliefs .I am considering this built short block for future use in a pickup .The pistons .063-.066 in the hole .What concerns me is intake manifold fitment .I have a pair of c8me heads I plan to use probably they have been milled as well so lets consider that also .I am wanting this build to get decent mileage if I have a .043 gasket the quench would be .106 or more and torque and gas mileage will suffer .This short block is fresh never ran the pistons and rings are new and I really don't want to change them .What are your thoughts ? Doug

[Heo]

I would put a 390 crank in it. probably cheaper than
machining the block.Must be a good supply of usable
390 cranks due to all stroker builds

[manofmerc]

Heo it has a 390 crank and rods + .050 over bore equals 390 cu.in

[Heo]

Why are the pistons so deep in the block what deckhight now?
10.155 usualy dont mess to much with intake fittment

[manofmerc]

Heo  These are cast pistons kind of common for them to have a lower compression height .Piston manufactures did this to lower compression .Not caring that doing so eliminates quench . I am curious about intake fitment .If my block is milled .050-.055 I will be at .008-.010 leaving a bit for future builds . And maybe I should mention my intake choices I have a c5 cast iron and a f427 .This is a 4500 rpm truck engine no high winder so that's where I am at I haven't had a block cut this much before this is un chartered territory for me .Doug

[Heo]

10.17 is stock height.Often higher that that on a untouched block
and  differs from end to end and side to side. My last block use
speed pro forged flattops ended up zero with 10.155, Differed 0.030
from end to end on one side before machining       
No big issue with intake fittment just slight on VC rail in one corner

[blykins]

I don't think I'd ruin a block for that. 

You will also have to cut the intake manifold extensively and there's also a chance that you may run into pushrod tube clearance issues. 

With all of the milling money that you'll be spending, I think I'd just get a new set of pistons, or run a thin head gasket and just roll with it.  If you ever decide to sell, no one will want a block that's been milled to death.

[FElony]

Do you have the part number off the pistons? Maybe you would up with 410's, which are often sold as 70's 390 truck pistons.

[TomP]

I'd use the steel shim gaskets. I think those came on the 70's trucks that had the 410 pistons.

[manofmerc]

I have thought about the steel shim gaskets .Maybe cut .020 off the deck and see what it would work out to be .I bought the pistons off the old forum new in a federal mogul box .thanks for the replies .Believe me I was surprised to see how low they were .Thank you all Doug !

[Falcon67]

I don't think I'd ruin a block for that. 

You will also have to cut the intake manifold extensively and there's also a chance that you may run into pushrod tube clearance issues. 

With all of the milling money that you'll be spending, I think I'd just get a new set of pistons, or run a thin head gasket and just roll with it.  If you ever decide to sell, no one will want a block that's been milled to death.

X2 - I would not even consider cutting that much off a block.  Most I've ever had to do is .016 and I fussed about that.  Weakens the deck too IMHO.  Make it right with a quality piston and you'll have an all around easier time of building it.