samtset

I have my 85 tpi 5.0 iroc..the engine is tired and I had a old style 5.7(non center bolt valve cover) goodwrench motor given to me that runs like a champ. It is however carbed and I want to put my 5.0 tpi intake and stuff on it. Questions, i heard the knock sensors are diff, do I pop mine out of my 5.0 and put it on ther 5.7, what injectors do I use and do I just keep using my ecm? Should I expect any drivability problems with this swap since 5.0 stuff is now going on a 5.7? how will the ecm react to the extra air/fuel the engine will now consume? If it isnt clear, I am using the 5.7 longblock.

five7kid

iTrader: (14)

Get a 350 knock sensor and module. The Goodwrench engines had pretty lame cam, heads, and compression, so your 305 injectors should work without any problems. The system is mass air flow sensing, so the extra displacement won't be a problem for it. It'll probably run like the 305 did when new.

If it was my project, I'd put the 305 heads on the 350, and put a better cam (with new lifters) in it while it was apart. That might put you into needing 350 injectors, but that's a small price to pay. Refreshing the heads and new valve springs would also be my approach. If it was my project...

samtset

well since this is such a lame upgrade can i just use the 5.0 knock sensor and use my 5.0 module?

five7kid

iTrader: (14)

No, because the knock sensor is tuned to the cylinder diameter, not to the performance level.

The Goodwrench 350 was intended as an inexpensive replacement for general purpose use, like fleet vehicles. I had one in my '84 full size conversion van (replaced the 305 the factory had installed). It ran fine, we used it to pull a 2-horse trailer. But, it wasn't exactly a barn-burner. The heads have large chambers and poorly-flowing ports. The pistons are dished. GM puts a little better cam in it to bump the horsepower from 260 to 290 (gross flywheel HP, not the net flywheel HP that is used to rate engine options) to make a "performance" crate engine.

There have been numerous magazine articles on upgrading the Goodwrench 350 engine; the first things replaced are always the cam & heads.

Your 305 TPI had 9.5:1 compression from the factory. The Goodwrench 350 has 8.0:1. Putting the 305 heads on it will bump the compression up to about 9.0:1. That, plus the extra displacement, and a little better cam, will boost performance considerably over just installing the engine as-is.

I hope that helps explain my use of the word "lame". It was intended as information, not in any way, shape, or form as a slam.

samtset

haha no insult taken, I personally felt it as a lame upgrade myself lol. I just have a million projects going on so I wasnt too willing to go crazy on this one, I appreictae all your insight, so I will get the 5.7's knock sensor and run that in there. Today will be fire up day and madien voyage as well. Ill let ya know how it runs, thanks again!

samtset

Lastly you said change the module? like the ecu? I have a 5.0 ecu should i change the prom in it? so far i have the stock 5.0 injectors and a 5.7 knock, EVERYTHING else is from the 5.0.