[ChadGresham]

I decided to try my luck with replacing valve stem seals on my 1986 Chevy C10 with carbureted 4.3 liter the other day. . I rented one of the clamp type valve spring compressors from autozone, because i don't think i would have had enough room for the lever type one. I followed my Haynes manual VERY closely making sure not to screw up. After i finished cylinder 1 and 6 and was on 5, my rented tool came apart, (E clip came off the bottom) so i had to use a rubber grommet to hold her together long enough to finish the job. Valve stem seals are simple to replace with the right tools, and proper instructions. One thing i found that was not meantioned anywhere is you need to put the rubber O-rings on AFTER you put the positive seal or umbrella on AND the spring. Other wise the O-ring will slip down and be useless!! Also adjusting the valves when done.. My manual said to tighten the rockers till you get drag on the pushrod, (twist it between index finger and thumb) and then they said tighen an extra 3/4 of a turn! On my engine this was causing the valves to open slightly. Luckily my dad has serviced valves before so we wound up tightening till i could barely turn the rod and THATS IT. No valve train noise so we must have done pretty well.

[ChevelleSS_LS6]

I've always found that Haynes manuals tend to leave out subtle, yet important details like that. I've had better luck with Chilton, but not as much experience using Chilton manuals (Haynes are more readily available... and better than nothing).

[ChadGresham]

Yes and on top of that there is not much information out there on tuning 4.3 liter engines. Just not as popular as Chevy 350s, but everytime i do something major with mine, i try to post about it and enlighten people who may be in my situation

[BOBCRMAN@aol.com]

If you use positive seals on a SBC or 4.3. The o-rings are not necessary. GM phased them out in late eighties, after using up inventory.

[ChadGresham]

Mine is an 1986 4.3 and it had both positive seals and o-rings so i put new ones on. There were no umbrellas on the exhaust valves when i took valve covers off but i went back with them since they came with the kit