smoke on start up

Guys
I am a new member, and I hope somebody has their thinking cap on. I have a 427 bored .60" over ( 440) the list is long ....
Canfield 310 series heads / solid roller cam / apx 11:1 compression with TRW forged pistons / RPM air gap / etc etc.
This engine has about 1500 miles on it since new rebuild...........runs very strong.
Problem........smoke on start up , not initially, but after she has run and is warmed up.
Recent rod run ( apx. 250 miles) she used about 3/4 quart of oil.
No smoke when I decell down hill ( guides / valve seals) and of course the heads , as well as everything else is was (is) brand new,built and machined by respected veterans .We installed new viton seals after we set up the heads for the roller cam. I thought about potential intake manifold leak, as the canfield heads are short a couple of intake manifold holes, but I haven't taken it aprt untill I have a couple of solid ideas. As everything is pretty much new,I am kind of scratching my head on this one.
Could sure use some help
thanks
Dave:confused:

AJust a few things to look for.
1. Piston to cylinder clearance. Forged pistons generally require a bit more clearance than cast pistons, and sometimes create the condition you are experiencing, or the clearance may actually be too much. Check the specs for your pistons.
2. Are the valve seals still in their proper place. Sometimes they can move.
3.Is the intake sealed up good?
4.I would pull all the spark plugs and see which cylinders are getting too much oil, and do a compression test to see if all the cylinders are sealing up equally. Could be that some cylinders are sealing tighter. Have heard of the quality of some pistons having deteriorated lately, as in not holding consistent dimensions, resulting in poor piston to cylinder wall clearances.
5.Piston rings installed upside down can cause this condition
6.Not to scare you, but make sure there are no cracks in block or heads, but with all new or re-machined parts, that should not be a problem, but it has happened!
7.Could just need to break in for a little longer, put some miles on the engine and see if it gets better. May not even be a problem.
Hope you find the problem, and when it is fixed, you will enjoy your car that much more for a challenge that was conquered.

it is not the intake for lack of the upper two bolts on each side i used many intakes that is not it .it just could be like said it may need more mile s on it .was the block plate honed ? some have gone to i very fine finsh on there bore then go over that with a plateau hone could be the rings are not hooking up good ?? hard to say .pistons could be abit loose but when warm they can grow abit so they would stop rocking a round in the bore helping the rings to seal .some of the old timmers do not like to run the pistons as close of runing clearances. with the new alloys they do not grow like a older TRW so they need about 1/2 of what we used on the trw less he could of set your bbc for kill and by that she loose . if there getting beat on hard with power adders as it would not be set up like for stock use .i would look at a better oil ? you did not say what your using .but i would only run a w40 or w30 in it for 500 or more miles before you go to a full synthetic and i would not wast money on it :D . it could smoke some tuneup could be off . you do not have a choke ?your oil could be getting fuel dump in it .as well as no pvc or poor breathers could be pushing oil out as well or abit of every thing .and big block s can use abit of oil with big bores and big strokes your beating oil up on the walls making a bigger job for the rings as well as the beathers or pcv your cr can add to this as well .a set of low tension oil rings can add to this

Sounds like the rings never seated right. How did you run it in? The first ten minutes of an engine's life is the make-it-or-break-it time. I like to have them fire up quickly and run at 2000 RPM for those 10 minutes, never have any problems that way. Of course, that doesn't always work out, leaks happen, or dumb mistakes don't let it start right up, etc.