Intake swap questions.

[C54]

I am building a some what mild 350 out of a 70's truck sbc for my rat. I originally bought a air gap rpm performer for it, but recently bought a edelbrock tr1yx tunnel ram for it. This intake has the oil fill tube in it. Do I need to do anything to the block? I would like to run a set of the old script valve covers with it. I have read pre 68 blocks had a vent on te back side of the block. Will I need this?


Oh and the cam I am running has a rpm range from 3200 to 6000. That coupled with a 3 spd I should turn enough rpm to use the tunnel ram.

 

[26Troadster]

you will need to have a breather of some kind so it doesn't build pressure in the block. a breather on the fill tube should be enough if your oil returns in your heads are not blocked. the cam sounds good for the intake but i don't believe you will run them r's cruzin around.

 

[zzrodder]

The older small blocks had the vent tube at the back to draw out the fumes - it's called a road draft tube. '68 and newer used a breather on one valve cover and a PCV valve on the other one to the carb.
For your setup, it would be best to plug the filler/breather hole in the manifold with a frost plug and go with the breather and PCV in opposite valve covers. Using only the breather in the fill tube will end up creating sludge, it needs the extra draw of a PCV to properly evacuate the fumes and drawing from valve cover to the other would work better than from the vent tube to one cover. Another option would be a PCV in each valve cover Tee'd together and going into one carb, then you could keep the vent/filler tube.

 

[Gastrick]

You can also place a pcv in the breather tube like some of the 60's Corvettes, Camaros etc had. You can still get these (and the associated parts) from the aftermarket/reproduction suppliers.

 

[C54]

Thanks for all the help guys. Gas where would a guy look in the aftermarket world for one of those?

 

[Gastrick]

Ecklers has them

http://www.ecklersnova.com/nova-engine-oil-filler-tube-black-with-threaded-pcv-port-1967.html

Also, Long Island Corvette...
http://www.parts123.com/parts123/yb.dll?parta~partsort~1~cadeikba

You could check ebay too for pricing. Search for Oil Fill Tube PCV. You could make your own but keep in mind they have a sealed, twist on type cap, so you would need to add that feature also.

 

[C54]

Thanks for the info!