I was about to post this info in the theoretical and street racing forum, but figured it would get more hits here.

This is a pretty good comparison to fuel the constant 305 vs 350 debate.

LG4 305 Gross Dyno numbers
Headers, Flowmasters, non computer Q-Jet , HEI

Baseline ----------------197HP @ 4600 ------- 261TQ @ 3100
+Performer Intake---- 217HP @ 4200 ------- 285TQ @ 3300
RPM Intake ------------ 231HP @ 4800 ------- 285TQ @ 3300
Victor Jr / 750 Hol ---- 228HP @ 4700 ------- 291TQ @ 3500

+X-treme 218/224 ---- 270HP @ 5100 ------- 291TQ @ 3700
__ (vacuum 20” to 14.5” – however very little low end loss )

+Vortec heads and
Super Victor intake --- 325HP @ 5800 -------- 317TQ @ 4800

+AFR 1.99/1.55 58cc
Uncapped exhaust
Perf RPM, mod 650 – 387HP @ 6000 -------- 368TQ @ 4000

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Goodwrench 350 - Gross Dyno numbers
L98 manifolds, Flowmasters, Q-Jet, LG4 intake, stock cam

Baseline ----------------- 230HP @ 4500 ------- 320TQ @ 3000
+Performer&headers - 258HP @ 4500 ------- 331TQ @ 3100

+218/228 – 112 cam – 309HP @ 5500 ------- 354TQ @ 3750

+Vortecs, Performer
+X-treme 224/230 ----- 376HP @ 5700 ------- 395TQ @ 4300

+SuperVic750 Demon- 395HP @ 5700 ------- 398TQ @ 4300

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350 ZZ4 -headers 3”duals
Baseline ------------------- 349HP @ 5400 -------- 380TQ @ 4100
+268 cam, RPM, 750 -- 380HP @ 5400 -------- 402TQ @ 4100

The 305 and the 350 Goodwrench engine were similar enough I felt like the comparison is pretty valid. They were done on different dynos,, so there is margin for error. I threw in the ZZ4 cause that seems to be a pretty popular engine on the 3rd gen boards. Computer simulations of these combinations yield near identical results as posted,, another validation in my mind. Enjoy the info.

 

I wonder how the 350 would have responded to the AFR's and a Performer RPM intake? I wonder if there's another 80HP and 60ft/lbs of torque left somewhere waiting to come out?

I'll tell ya though, If I were Edelbrock, I'd have those dyno numbers on every Performer and RPM Performer intake I sold, seems like pretty impressive gains on the 305.

 

Theres some pretty imressive numbers on the 305 IMO.

What would having the L69 engine instead of the LG4 do to those numbers and just how much of those mods are street legal?

I dont know much about modyfying engines etc thats why Im asking. Im also curious about what happens when you do these kinda modifications and go to get an inspection/emmisions test etc.

 

Those numbers seem to match what I was thinking along the lines of my 305 "210hp yet to be on a dyno"
Do these number include the smog pump?
Im thinking they dont because there non cc but thats why I ask.
SSC

 

those are really impressive numbers. i had no idea the heads, both vortec and AFR would yeild that much of a gain, the cam(s) also, they bumped the horses up alot more than i thought they would also.. all that power, waiting to be released, its amazing how much detuning gm must do befoer they let their cars off the line. (one of the best examples is the Buick GN's, with a very small amount of money, you can be running 11's, and drive the car every day on the street)

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83 Z28--not a pretty site, sold thank goodness

74 Z28-- 383/400, green on black. pretty clean. FOR SALE!!!