I am putting a vortec set up on my 69 Malibu with a 350 4 barrel. I have got the 64cc heads and the cam is a comp xe268 cam kit.I also have an air gap intake and and edelbrock 600cfm carb. Is there anylittle things that i wouldn't be thinking about that i would need during the install. I have all the gaskets. What thickness head gasket would i need to still run on cheap 89 octane pump gas?

onoj5; If the pistons are flat tops,standard .039" gaskets will yield about 9.7:1 static compression.With that and the XE268 cam,I would recommend 93 octane,with about 34 degrees total timing.I can't see it running safely on 89 octane without pulling out 4 or more degrees of timing,which would result in a serious power loss.As for the heads,are they stock?If so,you need to upgrade to a better(stiffer)spring,and check your retainer to seal clearance.You need at least .050" clearance from maximum valve lift to the springs coil bind(preferably .080-.100"),and about the same for retainer to valve seal.The stock Vortecs don't provide this,and have too little spring pressure for that cam. Steve

I have one with dished pistons and a milder XE256. I can run only 30 deg advance (which is about all the Vortecs like) and a very slow advance curve even with 91oct.

FYI...every set of stock Vortec heads I have measured were actually closer to 62cc.
I'd use that dimension when figuring your CR.

I think you could get away with 89 octane gas. Vortecs have very efficent combustion chambers and actually run better with less timing (32* works best for most people I know). I even know someone with close to 11.5:1 running fine on Sunoco 94 with Vortecs.

Your setup will be nearly identical to what I run in my truck. Here's what I've got.

-350 +.030
-cast rebuilder type flat tops .040 in the hole
-fel-pro .041x4.166 head gaskets
-9.4-1 compression with horrible quench
-vortec heads, upgraded with comp 981-16 springs and matching reatiners and locks (came with the k-kit). This was a drop in deal for me but I have heard of others have problems with these springs fitting over the guides. I did NO machining to my heads
-XE268 and stock gm guided rockers. I suspect the reason I don't have retainer to guide clearance problems is because stock rockers usually have a slightly less than advertised ratio. And unless you convert to screw in studs and guideplates, you HAVE to run guided rockers. The stock gm ones work fine and are around $50 a set. You can also get aftermarket guided roller tip and full roller rockers if you want.
-You will need centerbolt valve covers. I am using a set of stock replacement chevy truck valve covers, gaskets, vc bolts, and oil fill cap...all available (and cheap) thru any chevy dealership (I got my stuff from pace chevrolet)
-you will need vortec specific intake bolts and gaskets. Again, gm is the best source of this stuff. The intake gaskets are reuseable too.
-You may need an adapter for the temp gauge sender if yours screws into the heads. Most any auto parts store should have these. You will need a plug for one fo the temp sender holes also.
-you will need something like an autolite 6005 spark plug. These heads use a tapered seat plug with a long threaded area.

To date, I have run these combos on this engine. Performer rpm/600 edelbrock, performer rpm/750 edelbrock, and currently a performer (not rpm)/650 holley spreadbore. The rpm makes more power above 3K rpms, but the performer/spreadbore combo is WAY more responsive on the street, gets considerably better fuel economy, and just all around works better for my 3.08 geared, 4500 pound truck. And, it still pulls like crazy to 6K. I use a 2000 stall B&M holeshot convertor...a 2400 stall will work better with that cam because it really comes on strong about 2400-2500 rpms with a performer rpm intake. With my 9.4-1 compression, bad quench, and heavy weight, I run 89 octane with no trouble at all...even when towing. My particular setup runs best with 14* initial, 34* total. The cam pulls 14.5" vac at idle. With the performer rpm/600 edelbrock, it average 15.5mpg on the highway at 65-75 mph.
Any other questions? ;)

i have the thinnest head gaskets i could find under my Vortec heads- .015 Victor Reinz steel shims from a NAPA gasket set- on the 355 in my Nova with flat top forged pistons with 2 valve reliefs. i figure a hair over 10:1 compression ratio. with the GMPP HOT hydraulic roller cam and 1.6 roller rockers and timing set at 34 degrees total, it runs with no noticable detonation on 92 octane gas- and just a little bit of pinging with cheaper 91 octane if i try to go 15 mph in 4th gear or something. otherwise, it works great from 800 rpm up to 7000 rpm.
of course, my cam bleeds off a lot of cylinder pressure down low- i only have about 135-140 psi cranking pressure. a milder cam made for low end grunt that builds more cylinder pressure down low might be a different story, however.

Originally posted by onoj5:
I am putting a vortec set up on my 69 Malibu with a 350 4 barrel. I have got the 64cc heads and the cam is a comp xe268 cam kit.I also have an air gap intake and and edelbrock 600cfm carb. Is there anylittle things that i wouldn't be thinking about that i would need during the install. I have all the gaskets. What thickness head gasket would i need to still run on cheap 89 octane pump gas? Did you get this combo running yet? How does the cam work for you?

I ran stock type flat top 350 pistons in my 385 [5.56" rods] and right at 10:1 compression with a comp 268 high energy cam and a stock HEI on 91 octane for more then a year,no problems even at 115* outside. My vortec 350 does 9.4:1 with an even smaller cam and 87 octane. These heads resist detonation great smile.gif