Head rebuild
Thread Starter
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Mountain Pass
Joined: Sep 2007
Posts: 164
Likes: 1
From: NW Ohio
Head rebuild
I've got 93k original miles on my '78, and am ready to throw some parts at it. Currently in the mail, I have the Offy DP intake, Holley 390cfm, and the efi exhaust manifolds. While things are apart, is it a good idea to rebuild the head? It makes a little noise, but I've been told that's normal. I've also seen a reman head advertised as "without the air holes". What's that mean? Also, my original head should have the 3/8 studs compatable with the chevy I6 rockers, right?
Posting Guru
Joined: Sep 2004
Posts: 1,556
Likes: 5
Yep, people do the chevy rocker swap on the carb engines.
Some cylinder heads have holes that lead into each exhaust port, this is for air injection, some have it, some do not, I thought that was for efi engines (manual tranny with air holes, automatic tranny without).
Since you have your engine "torn down" and have go fast goodies on the way, have you considered adding a camshaft? Id imagine when you rebuild your head youll have new springs installed, and camshafts are still relatively inexpensive, when you think in terms of shelling out the dough for an intake/carb/efi exh manifolds. All manufacturers list rpm range, so its a no brainer.
Another suggestion.
If you have your head reworked, might not be a bad idea to consider having 1.94 intake valves installed, the exhaust valve stock are 1.56 so I dont see much of a need to open it up to the standard 1.6. Of course MILD port work wouldnt hurt anything if done right.
Add those to things to the "to be done" list and you might forget its a six banger, well, if you cant hear the exhaust.
I like your truck man, looks nice from what I can tell.
Good luck
Some cylinder heads have holes that lead into each exhaust port, this is for air injection, some have it, some do not, I thought that was for efi engines (manual tranny with air holes, automatic tranny without).
Since you have your engine "torn down" and have go fast goodies on the way, have you considered adding a camshaft? Id imagine when you rebuild your head youll have new springs installed, and camshafts are still relatively inexpensive, when you think in terms of shelling out the dough for an intake/carb/efi exh manifolds. All manufacturers list rpm range, so its a no brainer.
Another suggestion.
If you have your head reworked, might not be a bad idea to consider having 1.94 intake valves installed, the exhaust valve stock are 1.56 so I dont see much of a need to open it up to the standard 1.6. Of course MILD port work wouldnt hurt anything if done right.Add those to things to the "to be done" list and you might forget its a six banger, well, if you cant hear the exhaust.
I like your truck man, looks nice from what I can tell.
Good luck
Postmaster
Joined: Dec 2006
Posts: 3,603
Likes: 10
From: Spokane, WA
The head is a bottleneck to flow so mild porting/polishing with port matching with the manifolds and a three angle valve job with 30* back cut on the valves will help get the most out of your other mods. If you go with an after market cam get the recommended lifter kit too and have the press in studs removed and drill and tap for screw in studs.
The 390 will most likely require some adjustment. The main items are sometimes a larger pump squirter, blue pump cam, and sometimes heavier vac secondary spring.
The AIR holes are easily plugged with parts from an "Ace is the place" parts bin.
The 390 will most likely require some adjustment. The main items are sometimes a larger pump squirter, blue pump cam, and sometimes heavier vac secondary spring.
The AIR holes are easily plugged with parts from an "Ace is the place" parts bin.
Thread Starter
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Mountain Pass
Joined: Sep 2007
Posts: 164
Likes: 1
From: NW Ohio
Thanks for the input guys. I have been thinking cam too. Hafta see how much stimulus check I've got left, lol.
Here's a link to the rest of my truck pics 78 F-100 - a set on Flickr
Here's a link to the rest of my truck pics 78 F-100 - a set on Flickr
