Many engine builders won't deal with flat tappet anymore.

A few will relectuntantly and usually only if they can choose which core, lifters, and what type of oil you run. They'll still squint putting it together.

You are pretty close, but I think I can do it a little cheaper than that. It all depends on where you get the parts. I`ve got a good connection. I can get all my parts at wholesale / jobber or less.

I really doubt you can get a roller cam, roller lifters, timing set, valve springs, pushrods, retainers and locks for much less than 1k, but good luck. Thats whats needed. Using all Crane parts through Summit, it ran me about $1300.

Yes, definately tough to do much cheaper unless standard quality stuff is used or as Don said 'connections' .

Timing sets i get are typically around $100.

Pushrods I get are typically around $120-$160

Lifters around $550

etc,etc.

It adds up quick but then I buy HD stuff, not just replacements.

One advantage I have is someone has gone through these engines before. Already have Crane Gold Rockers, Good pushrods, locks, retainers and nice, tight true-roller timing chain set.

Crane gold rockers are a stock item on 420's. The pushrod length is different for a roller cam/lifters. The lifters are longer, so the pushrods need to be shorter. The timing chain set is different as it incorporates a bearing system that must be used with a roller set up. Also, if the rockers have a lot of hours, they should be replaced also.