Emmissions Equipment

[Johnny4576]

I am swapping my 305 out for a 350 in my 1984 GMC. I want to go non EGR as well if possible loose the rest of the emissions vacuum lines and check valves. I already have a edelbrock carb performer series non egr model and thinking about getting there non egr intake. AIR system with also be removed as well the TVS. The stock air cleaner and temperature sensor will not be there either, the EFE system will be replaced too and the canister will only vent the tank not back to the carb. Looking for some answers on these check valves and if all of these are necessary. 

[eventhorizon66]

I did the exact same thing when I swapped in my Goodwrench 350.  The only thing I am running is the EVAP charcoal canister.  I kept the thermal valve that only allows vacuum to the EVAP purge valve (at the charcoal canister) when the engine is warm.  Everything else was scrapped and I've had no issues.  The EVAP canister must have a purge line running back to the engine.  I am running my purge line tee'd in with the PCV vacuum line, without issue.  VileZambonie (arguably THE guru to turn to here) says this is wrong and it should be vented to the air cleaner with an inline check valve, but as far as I can tell, my way is how the factory did it (based on diagrams I've found and pics I took before dismanteling my 305).  Maybe you want to hear from him before hooking the EVAP back up.

[Johnny4576]

The TVS on top of the thermostat housing is what i am scraping and putting an older style housing on

[VileZambonie]

If you are running an aftermarket air cleaner and carb that is one way to do it. If your running the Q-jet you can still leave the evap system in tact as is. Tee'd into the pcv system was oem.

[eventhorizon66]

He said he's running an Edelbrock carb like me.

Here's a pic I posted elsewhere here before.

[VileZambonie]

You can tee into the pcv system but only if it's after the PCV valve. A backfire would be an ugly scene. lol The Tee in on the PCV hose before the valve is only for vacuum control.

[eventhorizon66]

Well I have it kinda at the PCV valve as the vent line passes its general vicinity.  Maybe a one way check valve for the PCV would be a good idea, huh?  And I did have a few backfires while dialing in the carb/ignition. But I didn't blow the driver-side valvecover through the hood, so all is well.

Not to hijack your thread here Johnny4576, but I figure this discussion will help both of us.

[Johnny4576]

no problem here I am glad u gave a pic.. I will post some tomorrow to help ID some items just for my knowledge.

[eventhorizon66]

Just so you know, here is the thermal valve I use for the EVAP canister.