I have an 84 Z28 with a 350 short block put in by the last owner. All of the other 305 stuff is on it....heads, carb. It does have edelbrock headers, with the AIR.
I am putting on some vortec heads, (903's), and a Cliff's high performance late 70s Qjet, and maybe some 1.6 roller rockers. I know that I'll have to machine the valve guides, and studs for guide plates. It has a "3/4" race cam....not to sure what it is, but not factory.
So here's the deal. I'm putting in the old style HEI, and the carb....I've removed the computer, and wiring harness to it completely. The car has air conditioning (yikes, the brackets for that are fort knox!) which I'd like to keep. What do I need to do about the wiring? There are several sensor modules on the drivers side cowl which I haven't taken out the wires on yet because there seems to be wires that are for other things in the loom. Is there a place where I can get a schematic that lets me know what I can dump, and what has to stay, and where it goes?

 

Well, there is not telling what cam it has, that terminology is dead. As for the rest, i just remove all wires that do not do anything.

 

So how do you tell which wires do nothing if the engine is out of the car? Do you just back trace each wire from the thing thing like the lights, heater, etc? Also, do any vacuum lines need to be left in place?, and is there a way to continue to use the charcoal canister? Is there a manuel that would have this information?

 

A chilton would help with the diagrams. But everything that went to the engine for emissions can go, i never use the canister. I use the red power wire for the ignition.

 

+1on the Chilton. You can pick one up at a swap meat for cheap. It helped me a lot with wiring diagrams.

 

'nother question about the change over. I've been picking up some more parts, and I have a question. I have the '906 heads apart, and have picked up some roller tipped rockers. they are the self quiding type, Got some new springs good for .550 lift, with new retainers and keepers. Got a Crane energizer 272 H....454 lift on I & E. I also will be installing shoulderless screw in studs. A couple of questions. First, how long of pushrods do I need? Are they different for the vortec heads vs. the standard heads? Also, Doed anyone know of some online pics of how much (or little) clean up to do to the ports for the best result. This won't be my first set of heads, and I work with a small die grinder everyday, so the work will be easy, but I need to NOT wreck the heads by overdoing it. It's my understanding that the shape of the ports on these heads is pretty good as is. Also, is there any tricky way to pull these studs myself?

 

Well lets see...The pushrods will be stock length for whatever cam you use.

The heads should just be cartridge rolled to smooth them out and a touch of bowl cleaning, polish the chambers and unshroud the intake valve a bit where the spark plug is.

Let a machine shop do the studs.

 

Thanks, I thought so. As to the studs, Why? They are the kind without the hex at the bottom. Do you think that cutting the threads is potential trouble, or just too hard to pull out the old studs?

 

The bundle of wires that come up from the passenger fender well are the computer wires. They go to a pass-through connector into the passenger compartment behind the plastic fender liner. You don't have to cut anything to remove them. The only thing you'll lose that you need is the torque converter lock-up (if you have a TH200C or TH700R-4).

You will need the vacuum line that goes to the heater control. If you keep the vapor canister, you'll need those vacuum lines as well. You can keep the vapor canister without modification, as it isn't computer controlled. The carb you put on will have to have the fuel bowl recovery fitting like the stock carb, although if it doesn't, all you have to do is plug that hose on the stock system.

There are two ways to do screw-in studs - the "repair" type that don't have the hex (need to pull the old studs and tap the bosses); the "hex" type - using them requires milling the top of the stud bosses to get the proper location and to give the hex shoulder a proper surface to snug up against.

 

I know that I seem to be thinking of bits and pieces that would have been better asked all at once, but oh well!
I noted above that I'm using a set of vortec (906) heads. I am going to be using a crane energizer cam, with 272 duration, .454 lift specs. This would be fine for the current valve seal limitations which seem to max out at .490 lift, or else I would have to machine the guides for clearance if the lift is higher. I have a brand new set of roller rockers, but they are the 1.6 variety. I would have to have the stud bosses machined for studs compatible with guide plates, though, and I've seen that I have to choose between raised, or flat guide plates. Which would I need? And, I also know that I'd need to get the hardened push rods. Still the stock length?, and what is that length? Also, it looks like I'd still be under the .490 limit on lift.....am I getting into trouble otherwise with these rockers as opposed to the 1.52 rockers?

 

It would be about 484 lift with that rocker comb, i hear over .470 lift the might need machining, i also hear .490, not sure which is right.

 

So, machining or not, would I be better off....are there any reliability issues? Also, do you know about the difference between the flat guide plates, and the raised ones? I have a set of roller rockers that are not self guided