is it ness ary to use a off set roller lifter with these heads and there .800 off sea rocker arms.

I use offset lifter's on the intake side only. I have jesel offset rockers.

NO
Some mega blocks and a few others require some grinding on the block for pushrod room at or near the deck of the block ( you will see where at mock up ) the push rods are in at an angle and it is said that there is some power in going with offset lifters and getting them straight but unless you have the lifter bores bushed you can't use them as the only offset lifters available are not solid body and could cause oil pressure issues go with standard lifters and let her rock!

You must use the offset rocker arms. But only a few applications need to use the offset lifters.

Interesting , i've got solid roller lifters with offset intakes , mega block with jessel valve gear on 573-13 heads , are you saying the lifter bores should be bushed? , the pushrods don't come straight up either.

I was concerned about the angle from 440-1 rocker arm to a standard roller lifter.

I use a 400 deck height block with my 440-1's and use standard lifters.

I ran the standard offset full body Comp solid roller lifters for years, using the Jesel 1.7 rocker system. This was with a 71 year 440 block.

I've never herd of those lifters before.

I should of used the off set lifters with my victors. it would have made the pushrod clearance much easier. (a lot less grinding and machining) but of course when the victors came out nobody knew exactly what to do.....

This picture might be a little better.