i just purchased an 84 z28 w/ a 305 ho 5spd and i'm looking to upgrade the motor. it currently is stock except edelbrock 2101 intake, 1406 carb, and mallory unilite distributor w/ vac. advance. also has 1 5/8" shorty headers no cat and full 3" flowmaster.

i'm looking to change the cam and also heads if they should be. i'd like a good performance boost and also like a nice noticeable lopey idle.

i'm looking for some recommendations on a good cam/lifter/spring kit and also if i should get different heads. i'd like to keep the budget slightly on the lower side. i've read that this kit would work nice w/ the factory heads. not sure how good it would be though.

http://www.summitracing.com/parts/cc...make/chevrolet

also would roller tip rockers be good to add?

thanks a lot.

 

does anyone have any suggestions? i know its "only a 305" but i'm only putting the cam in so i have something with some performance while i build a 350. i want to take my time doing the 350 so i can put everything into that i want to. the 305 with everything that i've mentioned already on it plus cam and heads should do well until my 350 is done. from some of the reading i've done ppl are making some well performing 305's. i just need some help choosing the cam and if i can keep the stock heads and just use the lifters and springs that come in the kit or if i need to get a set of aluminum heads. i'd also like to get pushrods and roller tip rockers.. any help/suggestions will be greatly appreciated. i'm looking at $1000-$1500 at the most.

 

anyone?? please help...

the first link to a cam might have been a mistake.. i'm not sure.. but i have seen recommendations on this cam.

http://www.summitracing.com/parts/cca-12-210-2

 

The choice of heads is the limitation on the 305. You can't slap on a typical set of aftermarket 350 small block heads with 2.02/1.60 valves. They'll drop compression and the 2.02" valve won't clear the tiny bore of the 305.

Trick Flow is the ONLY company I am aware of that makes a 305-specific performance head (they're aluminum). They're not cheap, but they do work.

L31 350 Vortec heads are your other option but they will drop compession (slightly) and they require the use of a Vortec-specific intake and self-aligning rocker arms to complete the conversion (adding cost to what seems at first to be a budget upgrade).

Or you could pay some bucks and have your current -416 heads ported, good valve job, upgrade the springs, etc.

There's no "great" options here, just options.

Cam selection would be typical but realize that any cam in a 305 is going to act a bit more radical than it will in a comparable 350. Your stock L69 cam is 202/206* @ .050 on a 115* LSA with lift in the low .400 range, if memory serves. Just to give you a point of comparison while you're looking at aftermarket cams.

 

Just out of curiosity, any ideas how many bucks this would run? Also, if anybody knows, what should I look for in a new cam that would give a flatter torque curve. I know I'll never make huge power from a 305 TBI, but I'd like to boost it a little bit.

 

Kevo- 305 TBI heads (-187) are not the same as the heads on earlier 305 carb motors (-416). Your heads are the "swirl port" heads with half the intake port blocked off behind the intake valve to accomodate the "swirl ramp". Porting them out I would have no idea the cost or even where you could find somebody willing to tackle that job. It's been done- board members have had them ported, but it's not an everyday occurrance.

Exhaust upgrades are the best route with a TBI eninge (really, with any 3rd Gen engine). Shortie headers, 3" y-pipe and cat, 3" cat-back system. Beyond that, look on the TBI section of the board for "ultimate TBI mods"- mostly free or low cost stuff you can do. Modest cam upgrades can certainly be done as well, but not without addressing the chip programming at the same time to take advantage of it. TBI engines have crap programming even for the stock engine. Throw in some mods and it only gets further and further from optimum.

 

Thanks, I guess I'll spend a few more hours in research. I wish I knew more when I bought the car 20 years ago...

 

well leaving the q jet on it and the ignition system alone would have been fine, when working properly they already work as best as anything else in their place, the cam (if it really is an l69) is nearly identical to the l98 cam and is pretty good already. as already stated if you want better heads you'll either have to port your own or spend big money. not alot out there for the l69 lucky you already have a 5spd. i know it sounds a bit after school special but a good tune up of whats already in place and making sure your carb is in tune and all your filters/fluids are good is a better step them more go fast parts