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350 TBI roller cam conversion

8.5K views 7 replies 2 participants last post by  oldsg55  
#1 ·
Hello,

I am looking for a parts list needed to go from flat tappet to roller cam. I have a 92 g30 van with the 5.7 tbi. I can't recall the block number, but I do know it has factory drilled out bosses for the lifter hold down bracket that the roller cam blocks came with from factory.

I've tried looking into this, but I usually come up with information for a custom cam grind setup etc. I am just looking to swap out the solid lifter cam for a stock roller cam setup. From what I gather, a late 80s/early 90s caprice is what I need to source to get these parts? If anyone can confirm this or throw out other cars that have compatible engines I'd appreciate the info.

Do I need to get any sort of shim/different timing chain sprocket or does everything just transfer over fine in that regard?

Do I need to make any modifications to the lifter guides or do those parts work fine with my block as is considering it was already drilled and tapped to accept a roller cam setup? I ask because I've seen a video where people ground those down to sit closer to the head to properly fit the guides over the lifters, but I think they were doing some performance mod so it might not be applicable.

Are any of the valvetrain components different than the flat tappet, or should I buy all of that new either way (springs, pushrods, rockers...)?

Thank you
 
#3 ·
From my understanding, the flat tappet cam is not compatible with the roller lifters correct? So I would still need the cam?
Yes, the profile on a roller cam is different than the flat tappet. Does your block have the 2 holes in front for the cam plate too? FWIU you'll need valve springs to handle the higher ramp rates on a roller cam, are you keeping the 193 TBI swirl port heads? You'll need a timing chain set for a roller too.

Here's a picture of the front where the cam plate holes are. They may be tapped or not but you can do that yourself.
Image


BTW, that link you posted for the used parts is a great start.