| |
Labor Day Putting down your wrenches or time for
MORE wrenching? 
Plenty of places to share. | | Click on image for the lowdown. 
====
| | |
2 members (TUTS 59, JW51),
49
guests, and
1
robot. | | Key: Admin,
Global Mod,
Mod | | | Forums66 Topics128,009 Posts1,055,296 Members48,419 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | 
#71998 01/21/2007 12:37 AM | Joined: Jul 2005 Posts: 25 Junior Member | | Junior Member Joined: Jul 2005 Posts: 25 | I recently modified a HEI out of a 250 Chevy to
use in an 261 Chevy. Should the oil pump drive tang bottom out in the oil pump or should it be raised slightly and then the collar tightened?
Also I read somewhere that an o-ring groove could be machined in the housing and an o-ring
installed to minimize oil leakage. If this is so anyone have any specs for o-ring size and specs for the groove?
One more question--what spark plugs should be used with the installation of the HEI.
Thanks
arnie | | |
#71999 01/21/2007 1:58 AM | Joined: Feb 2005 Posts: 469 Shop Shark | | Shop Shark Joined: Feb 2005 Posts: 469 | The tang on the dizzy shouldn't bottom out if it dose it will cause extra wear in the oil pump. I've modified a couple of these without the o ring and not had leak problems although while you had the housing in the lathe you could turn a groove for a o ring. measure the shaft hole in the block and buy the o ring to fit then turn the groove to fit the o ring. | | |
#72000 01/21/2007 2:41 AM | Joined: May 2005 Posts: 1,624 Shop Shark | | Shop Shark Joined: May 2005 Posts: 1,624 | Have an aftermarket HEI Mallory in my 250 with no o-ring. Never had a leak there although my aftermarket finned push rod covers are a different matter. I agree that a little clearance between the tang and oil pump is a good idea.
Six volt guy living in a twelve volt world
| | |
#72001 01/21/2007 3:39 AM | Joined: Jan 2000 Posts: 2,074 'Bolter | | 'Bolter Joined: Jan 2000 Posts: 2,074 | Important to be sure the drive gear lines up as the original dist. Langdon's Stovebolt recommends the following with his Mini Hei for plugs'should be same for all HEIs.
"Suggested spark plug type is extended tip design, which is designated by a 'Y' suffix on Champion or 'S' suffix on AC brand, R44SX. Champion brand use RJ18YC6 or RJ12YC6." Also says, suggested gap is .060"-.080" for improved idle & low speed driveability".
And timing of 10 deg. to 18 deg, (without vacuum adv. connected.) | | |
#72002 01/22/2007 1:17 AM | Joined: Jul 2005 Posts: 25 Junior Member | | Junior Member Joined: Jul 2005 Posts: 25 | Thank you all for the info.
arnie | | |
|
|
| |
