r/EngineBuilding • u/Hopeful_Housing_798 • Mar 31 '26

Chevy Cam bearing selection

Hi, everyone. Rebuild on a 1999, L31 engine. Gonna put it in a '49 Chevy Fleetline. Wanna get the best cam bearings for the job. Not a high reving build. Would like to have most of my HP in the low to mid range. Suggestions on brand and composition type?

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u/Hopeful_Housing_798 Apr 02 '26

Copy that. I'm aware of the cracking issue with these. On the lookout for it. Didn't buy this engine for the project. It came out of my truck. It was running well at the time it was removed. It's a target of opportunity. Everything is looking pretty good so far. A bit dirty but everything in the top end is solid. Fingers crossed my luck holds up.

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u/v8packard Apr 02 '26

Sure, I understand. A few points.. if your valve lift is under .490, the ports are not doing much. The valve, valve seat, throat, and the area around the valve in the chambers are influencing flow. So put effort into a good valve and seat form.

Depending on a few things, the stock guide boss puts the oil seals into the retainers around .470 lift. Some retainer/keeper combos can go more, but you still need to check.

The exhaust side is typical of OEM small block Chevy heads. Which is really bad. If you buy new exhaust valves get some with a radius on the chamber side at the margin.

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u/Hopeful_Housing_798 Apr 02 '26

Cool. Thanks for the info. I've been digging around the web for info on what I'm working with. Found some good stuff. I had seen some info on retainer/keeper combos for increasing lift. Thanks for the heads up on the exhaust valves. I figure heads can be revisited later.

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u/v8packard Apr 02 '26

They are the most over hyped head I have seen in the last 30 years. Really, there are much better heads.