with conifers.. it is imperative to use the full latin name ... it really matters when using google ...

link below to images side .. look to leader growth for annual growth potential ... since you seem a newb.. let me say.. i think i see an annual rate in excess of a foot per year ...

i would site them at least 10 feet apart ... does that help your site block issue.. lol ...

ken

i hate when i forget the link .. lol ...

and flip to the ALL side after looking at the pix.. i note its a monrovia plant.. their website ought to give you good info ..

ken

https://www.google.com/search?q=Pinus+flexilis+%27Vanderwolf%27s+Pyramid%27&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjep8_DrPXMAhWRZj4KHVz-DloQ_AUIBygB&biw=906&bih=745&dpr=0.9

Thanks for the help :) I think that 3 of them will work out great!

I have seen this vigorous selection about 44' across at the Yakima Area Arboretum in Yakima, WA - an apparently heavily watered site in a hot-and-cold, low rainfall inter-mountain climate area. 'Glenmore', which I remember as similar looking was 63' tall (from a 1951 planting) in the Seattle arboretum by 1994 (cool maritime climate with very low summer rainfall totals).

http://www.conifers.org/pi/Pinus_flexilis.php