I have a 1981 z28.. it has a 350 bore 30 over..now i qould imagine that i would have some power...but the car hradly moves when i floor the pedal...no faster than a honda i have replaced the plug wires and that helped quite a bit but i am still lossing power somewhere if u have any ideas what so ever please let me know thank u

 

One thing to check is to make sure the secondaries on the Qjet are opening up if you are still using one. Some models have linkage to prevent secondary opening when choke is on. Over time linkage gets sloppy and prevents it full time.

 

You need to find out what the rear gears are on that 81Z? My 76, despite having a well built 400, barely moves with the stock 2.41's I have in there right now...

Also is that a stock 350, because the stock 350 that came in my 2nd gen put out 160hp, in a car that weighs over 4000lb's... youre gona get rolled by even the most basic honda's today.

 

Well gears dont make much of a difference. My 80 is pretty much stock besides the exhaust and shocks, and it has a TH350 and 3.42s but barely moves aswell. It has 64k miles and still runs pretty strong but i dunno i hope the comp cam and vortec heads will get it running a little better. These 2nd gens are so damn heavy though, supposedly mine weighs 3,660 according to nastyz28.com and my tittle but it has to weigh more to be this slow lol.

 

They make a huge difference, if you're running the stock 2.xx:1 ratio in a lot of 2nd gens, the car isn't going to move.. it's too heavy.

 

well idk whats up with ur guys second gens, but mine moves pretty damn well. i have a 81 z28. when i had the 355 in it. i still killed many a stangs and lt1s. my gear ratio is only 3.08s. but my motor had a mild build. depeneds on ur cam and carb, and tranny. if ur runing the old stock trans, u may lose alot of rwhp. my motor was strong enuff that i broke my trans in 1st gear. now im running a 383 stroker with a .563/.578 hyd. roller cam, ss mega monster trans from eatmyshift.com, and a 3400 stall. ls1's and the 03/04 supercharged cobras, i eat em up. if your running stock internals, ur ****ed. u aint gonna goo much on only a carb/intake/exhaust kit...for the 81, emissions killed us, soo take out that computer and exhaust restrictions, put duals, nice cam, and intake up. and bore that bitch, **** the q-jet. it sucks,. go holley or edelbrock. my 750 holley on my 383 stroker runs amazing,......

 

lot of power to be found in proper timing and jetting.

 

Need to know more about the combo. Are the engine internals stock? If it is a stock (except for the overbore) it will only be putting out about 175 hp (81 went computer controlled and lost 15 hp from the 80's 190 but 240 ft-lbs of torque or so). The stock cam is way small and should be the first thing swapped out.

 

I think only the California destined 81's got the computer. Canadian Z28's definitely didn't get the computer. They were identical to the 80's.

 

The computer controlled cars were California only in 1980 but should have been country wide on 81 models (at least U.S.).