69 L-78 Cam Specs?

[Bill Rose]

I'm having lack of vacuum problems with my L-78. I'm in the process of fine tuning the motor for max vacuum, but I'm also tossing around the idea of a cam change. I have a thread over on TC and those guys are a great help. I'm wondering if anyone has the cam specs for an original L-78 cam. If I do decide to change the cam, I will probably wait until the end of the season, but for now I'm trying to get an idea of where to go with this cam/vacuum thing...

[Donnie]

<span style="font-weight: bold">INTAKE and EXHAUST @.050 242 &amp; 242</span>
DURATION @ .020 285 &amp; 285
<span style="font-weight: bold">Gross Lift .520 &amp; .520</span>
Valve lash Hot .024 INT. &amp; .028 EXH.

[Chevy454]

what cam are you running now? the original l78 cam, or anything even remmotely close should have vacuum out the whazoo...my l72 pulls like 12 psi at idle?

[Bill Rose]

Thanks Donnie.

Rob, here's the thread on TC, that shows the cam specs. Which cam are you using?
http://www.chevelles.com/forums/showthread.php?t=319513

[Chevy454]

being a roller you don't have as much wiggle room, but you can gain some vacuum from adding some lash...it basically makes the cam looker smaller to the engine. i've seen some of the l88 &amp; zl1 guys run lash up over .035&quot; so they could pick up some vacuum. i run the crane blueprint (actually it's a cnc copy now), and have like 16&quot; around 1000-1200 rpms.

btw: if you'd like a stock 143 blueprint cam, i can probably get one for ya... <<GRAEMLIN_URL>>/wink.gif