I'd like to know if you had or didn't have to mill the guides w/your new cam. What lift cam was it and what head/valve train mods did it have?

Hi ukraine, I think I just went through the process you are going through now. I installed comp cams xe269HR (8-502-8) 218 224 .495int .503 exh. on a 112. I was told by comp that I would need springs # 986-16. And that these would require the seats to be cut. So I told the machine shop this, and they said that they could find some springs that would fit, without cutting.
So he assembles them and finds out he has to cut the guides down, and when he cut the guides down he realized that if he had cut the valve seat for the other springs. It would have cut the valve guide down at the same time. So either way they had to be machined, now I wish I would have just put the bigger comp. springs in. Hope this helps

nick

What engine/heads was this on? Do you know how much he had to mill them?

Sorry, this was on my 89 Trans am L98, He said the valve guides stock would take like .460 lift, he cut the down so they would handle .850. If I were you I would find a good machine shop and talk to them in advance. I went to one in adrian, mi. they are really good.