all you d.u.i users

[rusmannx]

I set my truck up with an HEI diz last year and have put on about 8k miles trouble free. I have been very happy with it, but carry spare cap, rotor, and module anyways. I have some opinions on this so feel free to disagree.

As to the gear issue. I used my Toyota gear but would not hesitate to keep the gm gear on if it was redrilled/repositioned as was done with the Toy gear. Take the two gaers and measure them! There is no such thing as metric vs sae when it comes to these gears. They are the same tooth count, pitch, angle of cut, and within a half a millimeter the same height. There is a slight difference in diameter because of the gm gear having a slight angled lead in ramp on the teeth ridge. It just means the tooth seats slightly deeper but as long as it doesn't bottom out there should not be any issue.

The reason most gears fail is because of the axial load not being supported by the bearing surface of the engine block. Look at the bottom edge of the stock gear and you will see it is polished from spinning against the block - as it should be. Without supporting the gear, the distributer shaft is pulled downward causing the star wheel to chew into the dist. housing, or in some peoples case, the gears missalign causing all kinds of wear.

I would think DUI has resolved these problems since they make their own custom parts, and maybe your drive gear was a dud that had improper hardening or something? But if I were you I'd inspect that cam gear since odds are it has some corresponding wear to what that drive gear has.

Good luck

so your telling me the GM gear will work?
or am i better off to find someone on this board with a used cruiser gear?

 

[iron_giant]

I don't know the specifics as far the sae vs. toyota gear. Cryptic seems to have a good understanding about this. My 2 cents. If it eases your mind then do what most of us who have done this swap do- change out the sae gear and put a toyota gear on it. Peace of mind is easily worth the 33 bucks. I ground the flange on my junkyard hei so that it would seat all the down and eliminate the problem stated above. Since you got the DUI unit for the 2f, you shouldn't have to worry about this.

As far as the advantages of the hei go. I switched from a non-usa distributor with a crane cams points eliminating set up to the junkyard hei. The higher spark and more agressive advance curve made a very noticable difference in starting, power, and acceleration.

The reason I asked about the comparison between of the 81-87 electronic toyota and hei set up is this: I have at home a large cap electronic toyota distributor on which the advance has been tacked welded. I plan on doing an EFI set-up on the f for which this distributor has been set-up to be computer controlled. The question is will I lose any significant gains by switching from the current Hei set-up to the large cap distributor?

 

[rusmannx]

um people... i have an F.
is the 2F gear different?

 

[dd113]

No, same gear.

 

[rusmannx]

whew.
thanks.