Distributor replacement clearance on a 72 with motor in the truck

[cameronsaddress]

hey guys,
I hope you are well!

Its time to replace my hei dizzy, but I am concerned about clearance since the firewall is so close. Have you replaced the dizzy with the motor in thr truck on a 72 blazer?

Any tips?

Thanks a million,
Cam

 

[bp71k5]

Just take the cap off first, it'll come out fine.

 

[72gmck5]

X2

 

[naranja72]

x3

 

[cameronsaddress]

Thanks guys!

I'll keep you posted...

One quick question. I am not confident that the PO had the dizzy in just right.

Do I need to find TDC on 1 first, then crank to 12 BTDC before I seat the new dizzy?

Obviously then,I'd set the firing order in the correct order around the distributor, starting with 1 in the original cap location, correct?

 

[72gmck5]

iirc the rotor only goes on one way so you shouldn't have to find tdc unless you're going to retime the engine

 

[cameronsaddress]

Thanks!

Actually, since it has run like a slug since I purchased it, I think I should retime everything.

Where would you start?

cam

 

[onetonbb74]

Find Tdc on number one cylinder, pull dizzy, reinstall new dizzy in same spot, adjust with the timing light, I like using an adjustable timing light so i can set it to 38 degrees total advance at 3000 rpm's.

 

[cameronsaddress]

cool, so no need for degreeing BTDC at all?

 

[bp71k5]

You need a timing light, but all the adjustment is done with the distributer installed. Just leave the clamp a tad loose so you can rotate the distributer to set the timing.

 

[ashman]

iirc the rotor only goes on one way so you shouldn't have to find tdc unless you're going to retime the engine

The rotor only goes on 1 way, but if you pull the whole dizzy out you can end up with it 180 out.

 

[sponsoredbydad]

My 2 cents : even if you don't want it. Removing and installing the dizzy with the hood removed is a very much more comfortable job(you can actually get your head in right over it). It only takes a few minuets to remove and if you scratch lines where the hinges line up it's easier to line up when it goes back on.