dusty84z

ok so the '84 Z28 I bought has the L69 H.O. 305 in it. the guy I got it from also had a running L03 out of a '90 RS that went with it. I'm thinking about pulling the L69 out and freshening it up. but then I got to thinking... I've seen a few 305 builds from car craft and popular hot rodding where they were getting in the low-mid 300 hp range with some simple mods using the stock short block. some even using original heads with some work.
now before anyone says it....no I'm not building a 350! I know you can make more hp for the same money, but thats not what this is about. the car came with a 5.0L and thats what I'm keeping in it. I'm not going for huge HP...300 at the crank would be fine with me. I'm not racing the car or anything...
I'm thinking about keeping the L69 short block since it has more compression and just doing rings/bearings. and I've already got a hyd/flat tappet crane cam that would be just about perfect for this build. but should I use the L03 heads? or are L69 heads better? either one would probably need 1.94 valves....or would it be more cost effective to just use some vortech heads?
If I used the L03 block I could use a roller cam...but then I'd have to buy another cam when I already have one sitting on the shelf.
what do you guys think? what would be the best combination of parts from these two engines to make a decent driver with moderate horsepower?
either way I plan on a cam/intake/carb/headers...

dusty84z

you know what... im stupid. I found in the 1990 tech data the L03 had 9.3 comp ratio....just BARELY less than the L69. so I may go ahead and use the L03 block. but I'd still like to know which heads are better....

Apeiron

The L69 heads, no question.

Air_Adam

L69 had a better cam and exhaust manifolds as well (similiar to the larger manifolds the L98 had). That said, aftermarket cams are cheap, and the L03 should be a roller engine already too. L69 wasn't a roller.

dusty84z

ok. so if I went with the L03 short block with the L69 heads (with 1.94's installed) a decent cam, intake, carb, and headers....I should be getting in the 300 hp range right? depending on how much the machine work would cost on the L69 heads, I could possible spring for some vortec heads and surely get past 300? thanks for the help guys!

oh by the way, this is the cam that I already have sitting on the shelf in my shop (still in the box) I figured it would be a pretty good grind for this motor. but its not roller...
http://www.summitracing.com/parts/CRN-10005/