Factory block isnt an issue running roller lifters. Many just drop in. Same with X block. Just drop in
59 degree R3 blocks are different in the lifter valley area than all others

Just for reference here is a 59* R1 with a Crane Roller lifter(old MP part#). This has been through Shady Dell's CNC Program. These lifters clear just fine but the comp 828-16 wouldn't and I had used them on a 360 block with no grinding in the past.

I used the Comp 8043 on my R1 and only had to cut the extra bolt bosses off. The 8043 has the link bars moved to the inside instead of being on the bore side of the block.

WOW!!!!! 4 year old post and I'm still running a solid lifter cam. LOL. Well it hasn't been all bad as the EDM lifters have held up well and its gone 5.98 in the 1/8 and 9.42 in the 1/4 running out get up and go on the top end. Which is really fine because every track I now race at runs 1/8 mile for my class. I was hoping to pull it and install another engine so I could freshen it but my get up and go got up and left. I changed the oil and transmission fluid, cut the oil filter apart (it looked GREAT) rebuilding the carb, new seat belts, and racing it. The 2019 race season is here.

LOL! I didn't pay any attention to the date, just replied after looking through it.

When my Dad and I built this engine comp was out of the 8043 and couldn't meet our timeline. My Dad reached into his small block archives and pulled out a 18 year old set of roller lifters brand new in the box and they worked great haha.

I saw the age of the post but added some info for anyone who may search in the future, I happen to have the heads off so it was easy to snap some pictures real quick.

Ryan at shady dell has a CNC program for that block to make a roller lifter fit

I saw that on his website but by time I drove out there twice I will have it done by hand. A lot cheaper too 😂

Just be careful, I understand there is a water jacket that sometimes makes a surprised appearance.

Like a said this is just my "bracket car" and running 6.0's is kind of a nice place to be. If and when I go to rebuild this engine I will see how the cam is holding up and go from there.

His "CNC" program is a joke, He runs an end mill straight down the valley knocking off the inboard head bolt bosses and shortening the lifter bosses. You still need to hand grind the valley walls for clearance.

I wound up getting an R3 block from a very good customer and I wound up doing a proper CNC profiling program that follows the contours of the block--It worked and looked really trick but it was not cheap. J.Rob

I have had him to two blocks and have been very pleased with the results.