[This message has been edited by Archie (edited 01-30-2015).]

[This message has been edited by infinitewill (edited 03-19-2015).]

quote Originally posted by dobey: Valve covers are the same for all LSx engines. LS1 has straight rockers and cathedral intake ports, while LS3 has offset rockers and "square" intake ports. Valve covers and coil brackets are the same on all Gen III/IV LSx/Vortec engines as far as mounting and gaskets go.

Not exactly... the 97-98 LS1's used a perimeter bolt pattern and the 99+ LSx versions used the center bolt style.


Also the as cast bosses for mounting the coil brackets have changed within the centerbolt years. I haven't studied them enough to know which ones are the same and which ones are different, but I know there are differences just from seeing used ones for sale on ebay. For example if you look at the bottom valve cover in both pics, the one on the bottom valve cover in the upper picture has a a couple more bolt bosses that the bottom one:

quote Originally posted by infinitewill: Hey Paul, I was wondering how familiar you are with the differences between LS4 heads vs. LS1/3 heads? Specifically, I have been looking for coil pack/valve covers and Eldelbrock has a few options but their tech line said they fit the LS1/3 only. Are the cover mounting studs differnt of the LS4s? Dr. W.

Will, are you looking at the cosmetic covers that mount over the coils to hide them? Something like these?


If that is the case, then you probably want to take a close look at the installation manual to see exactly how they mount to the coils/coil brackets. From this picture it would appear that the Edelbrock covers mount using the bosses on the valve covers, and then the coils bolt directly to the edelbrock cover and do not reuse the stock coil brackets.


Since they reuse the coil bracket mounting boss, find pics of both sides and look at them closely with some LS4 valve covers to make sure the bolt bosses are in the same place. If they are, then the edelbrock coil covers should bolt to the LS4 valve covers.

Then the issue is will the LS4 coils bolt to the underside of the edelbrock coil covers designed for the LS3. This coil relocation bracket below is advertized as fitting LS2, LS4, LS3 and LS7 coils - so that should mean the distance between the two mount holes are the same and that the LS4 coils should bolt to the underside of the edelbrock coil covers designed for the LS3 coils.
[URL=http://www.ebay.com/itm/LS2-LS3-LS4-LS7-bolt-on-coil-relocation-kit-powder-coat-black-12573190/281291998928?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D28774%26meid%3De0c69a698cbe4d1bbe1b0445384af2c1%26pid%3 D1000]http://www.ebay.com/itm/LS2...84af2c1%26pid%3D1000[/URL] 05%26rk%3D3%26rkt%3D6%26mehot%3Dpp%26sd%3D111609210005&rt=nc

Just for confirmation, I know the LS2 and LS4 coils are the same and I checked a couple of aftermarket coil mfg and they list the same coil for LS2, LS3 and LS7 applications.

[This message has been edited by fieroguru (edited 02-28-2015).]