01-07-2005, 08:38:00 PM
So, I have a nearly bone stock '81 z, 350 no computer, full exhaust (2.25" no cats h-pipe true dual)
I feel it needs more go, so this is my plan
-vortec cylinder heads (SDPC kit machined for .525")
-performer vortec intake manifold
-comp xe268h cam
A few questions.
Will the performer manifold still be low enough to clear the stock hood? would a performer RPM be low enough?
Is 350hp at the crank a realistic expectation with this combo?
Are there any problems with using this combo with the stock bottom end? in terms of bearings, lubrication, etc?
01-07-2005, 10:07:00 PM
I would say 350 hp is acceptable. Yes the RPM intake will fit under your stock hood. Get a open air cleaner with a drop base. A 2 3/4" filter will work. Instead of a rod and wing nut, use a long bolt instead. It'll leave enough clearance not hit the hood.
01-07-2005, 10:31:00 PM
<font face="Arial,Verdana" size="2">Originally posted by GoldenOne7710:
I would say 350 hp is acceptable. Yes the RPM intake will fit under your stock hood. Get a open air cleaner with a drop base. A 2 3/4" filter will work. Instead of a rod and wing nut, use a long bolt instead. It'll leave enough clearance not hit the hood.</font>
agree its sounds like a great combo what gear do you have?
01-07-2005, 11:21:00 PM
the hood is a solenoid cowl induction type, would i still be better off using an open air cleaner?
[This message has been edited by ZedMan (edited January 07, 2005).]
01-08-2005, 12:14:00 AM
If you are using Vortec heads, you may need to cut the rest of the air induction hole out of your hood so you will have air cleaner clearance. I ran Vortecs and the Vortec RPM intake with a 3310 Holley and could not get an air cleaner to fit under the stock flat hood of my '77 Z. The reason for that is because of the raised-runners of the Vortec heads. The RPM intake for the Vortecs is about 5/8" taller than a Victor Jr. single plane for regular small block heads. I run a Vic Jr and have more hood clearance now than I did with the Vortec intake. I should also point out I have polyurethane motor mounts, so I don't know if that raised my engine up slightly.
The fortunate part is you already have a factory cowl scoop so worse case scenario, you only need to cut out the rest of the exsiting hole in your hood.
The rest of your combo looks good - you'll love the power of those Vortec heads.
'Silver Bullet' 1977 Z-28 413" SB
11.73 @ 115.10 and dropping...
Old Vortec combo:
12.15 @ 110.52
1989 GTA L98
01-08-2005, 11:35:00 PM
One more question-- will the Q-jet fit on the performer RPM vortec manifold? the impression i got from edelbrock's site was it was for square bore.
01-09-2005, 03:00:00 AM
Not without an adapter plate in there.
You are correct, the RPM vortech is made for a square bore carb.
The only intakes I know of that will put a Q-jet on vortechs are the standard Performer Vortech, and the carb'd vortech manifold that GM makes.
01-09-2005, 10:15:00 PM
BluEyes is right. You'll need a adapter plate which means your clearance fears will become reality. I know you hate to give up a good running Q-jet as would I. But you might wanna look for a Holley or E-brock that will guarantee you clearance.
01-10-2005, 01:56:00 AM
okay, so is the performance difference between the performer and the performer RPM enough to justify buying a new carb?
01-11-2005, 10:13:00 AM
<font face="Arial,Verdana" size="2">Originally posted by ZedMan:
okay, so is the performance difference between the performer and the performer RPM enough to justify buying a new carb?</font>
In my opionion, NO.
I'm runnin a Performer style (prof. products) with a Q-Jet and love it. No clearance issues with the stock '79 Z28 hood, which dosn't have the cowl openning, so you should be golden for clearance with this setup.