LS5 Distributor Indexing confirmation

[Shane F.]

Hello from New Zealand,

I am in the process of replacing the spark plug leads on my 1970 LS5 when I discovered the distributor indexing incorrect. I have followed the recommended procedure - rotate engine to No.1 compression TDC, remove distributor & check dimple on the gear aligns with rotor. I have installed the distributor as per original indexing, rotor indexed to the correct No.1 location on the cap between inspection cover and vac cylinder. Cap hold down screws are now perpendicular to engine axis, the original factory stake marks line up between intake/dist housing. Unfortunately the Tacho cable boss is now pointing directly at the firewall therefore the cable will have an extremely tight radius. Also the hold down clamp is in an awkward position under the vac cylinder and the hose connection is untidy. If this is correct I now understand why the distributor was rotated to a more ergonomic position. I know the 327 configuration was changed for this reason, can someone please confirm if I have this correct.

Thanks and Regards Shane Fever.
NCRS New Zealand Chapter

[Owen L.]

Re: LS5 Distributor Indexing confirmation

The LS-5 distributor should be oriented such that the vacuum advance can outlet exits just about directly sideways toward the passenger side. This allows the vac outlet to be behind the spark plug wire bracket and the tach drive connection to be angled toward the driver's door. I believe this is specified in the AIMs as a modification to earlier installations.

[Shane F.]

Re: LS5 Distributor Indexing confirmation

Hi Owen,

Thankyou so much, you are correct. I have finally found it in the AIM, must have had a mans look the first time round. The configuration is indeed specific to the LS5, therefore it was correct to begin with. I began to doubt myself when the new lead set showed the standard orientation.

Kind Regards
Shane

[Duke W.]

Re: LS5 Distributor Indexing confirmation

Hello from New Zealand,

I have followed the recommended procedure - rotate engine to No.1 compression TDC,

NCRS New Zealand Chapter

Bad advice never seems to go away. Think about this. If you rotate the crank to align the balancer notch with the initial timing point BTC #1 compression stoke on the tab, this is when the points open that fires the plug. If you do as above at removal, then upon installation you rotate the distributor housing until the points just begin to open. This is called "static timing the engine". You can do it visually or with an ohmmeter, and with a little experience you will be right on, and the engine will start with no problem.

Of course the final step is to check either initial or total WOT advance with a timing light to be sure you got it right.

Duke

[Shane F.]

Re: LS5 Distributor Indexing confirmation

Thanks Duke,

Yes, very good advise. I thought it would be wise to set up at 6deg BTC #1 before removing distributor. I'll try the ohmmeter static timing and see how close I get.

Shane