Joe

The book says the info is on a sticker under the hood , nope

I can't rember, think it was 8 degree BTDC
Anyone Know`for sure ? 1990 L98

TPI BOY

on my 91 it's 6*

Lemme

I think the sticker is on the radiator on the drivers side. Talks about emissions in general.

Joe

On mine shows how to thread the serpentine belt

Joe

That should work !
90 and 91 are the same animal
Thank you very much , if we can get it running correctly we have a new old stock Paxton Super charger to install , made for a 90 or 91

Joe

spent 1/2 the day trying to get this done , used 3 diffrent kinds of paint to mark the balancer mark , Dam , had #1 cylinder on the wrong side

EastCoastHD

With that said,

Prior to setting the timing, did you disconnect the EST bypass?

Lemme

Here it is on the drivers side of the radiator on my 87



Says 6 deg BTDC and 0.035" plug gap

MyFirst90coupe

My 90 L98 says 6* BTDC

You must unplug the EST as someone said.

Joe

Yup we did , can,t figure it out , getting very bad fuel milage , no codes , black smoke and back firing , out of real side pipes ,well I did find a vacum line off under the throttle body , black smoke seems to be gone but running like poop ! Might need new plugs now

No sticker on my 90

90C4sRule

I have a pictures of the stickers but I can't attach them to this reply. I will put them in my corvette pictures.