Does anybody know what the biggest cam (duration, lift intake/exhaust) is that can be installed in a 91 z28 T5 tranny with a computer controlled 350 would be? What I'm looking for is something with a fair to rough idle that would be good for bracket racing! Engine that I'm building up has 10.5:1 4valve release 30 over pistons, 305 heads, stock tpi intake, stock computer and a JET fuel pressure regulator. Oh and I'm definately going roller.....Thanks in advance!!!

 

stock tpi intake is gonna kill you with a cam...most aggressive cams are gonna want to rev 5500+

and the TPI falls on it's face around 5000rpms. jsut not enough air flow.

not to mention the t5 won't last behind a cammed 350

 

funny, my T-5 lasted for 4 years behind a Hotcammed LT4 running 12.8's

 

I plan on also upgrading the t5 to a t56 once i save a little more money after the engine. Would a ram jet work? Besides hurting the wallet....

 

Holley Stealth Ram and fuel rails would be a cost effective way to extend RPM's...some modds required but a relatively cheap way to go.
305 heads, not a good choice, IMO, better to port the stock heads, or go with low cost aftermarket heads like World Products etc..10.5:1 is high for street use, stock '91 350 heads are 64cc , 9.8:1 anyways...
*Biggest cam depends on many factors;
*Heads that can support lift and flow.
*Rear and tranny gears to stay in powerband.
*Injectors and fuel pump to feed it.
*Computer modds to deal with vacuum drop and fuel needs.
*intake and headers to move the extra air...etc..etc...

 

Before you do anything else, get rid of the 305 heads, they are hurting your performance no doubt, they have small ports and tiny valves for the 350 not to mention a 55cc combustion chamber, it is common knowledge to avoid using 305 heads on a 350 as they will hurt you more than help...

10.5:1 on iron heads is not a good idea either when using pump gas, that high you should be running aluminum heads and 93 octane...

Seriously take this into consideration, you will benefit from this, I garantee you.

if money is an issue...the stock L98 iron heads are cheap and can be ported pretty well, the vette aluminum L98 heads can be had for about 600 and have a 58cc chamber for retaining a compression ratio of above 10:1, vortecs are good raised runner design that have impressive numbers for low cost...before you do the cam, get rid of those 305 heads, any engine builder will tell you not to do that.

After that, the LT4 hot cam is a good choice, even the ZZ4 cam isn't bad and it's pretty street friendly.

oh and for the intake, if you want to ditch the LT runner style for upper rpm horspower the HSR is a very effective and cheap way of doing this, the Miniram is over a grand and so is the Superram, the ramjet isn't cheap either...HSR may be intimidating because you need to get fittings for the fuel lines and run some braided hoses to the back of it but it can be done for about 100 bucks, on a sale day at thunderracing.com you could pick up the plenum/base and fuel rails with adj regulator for 480 bucks, less than half the cost of the miniram...pulling all the way to 6500rpm is awesome.

 

I got my ZZ4 Rollercam for $180 from GMPP.

 

Thanks for the detailed information Kiroc89! That definately helps me on what I'm looking at...