LS1 valve springs on a 3400

[DarksideGA]

Hey guys I have been doing some research on swapping out my stock 3400 valve springs to Ls1 springs. I've orderd 12 Ls1 valve seats, and just orderd my 3.1 MPFI vin "t" valve seals, and am about to pick up a set of the Ls1 springs. I am not planning to do any type of cam shaft modification, so my question is, are there any other items I will need to make these work on my 3400, or will it be a clean swap with the parts mentioned above. I know there are other threads on the topic but they are not 100% clear to me. I am having a shop install them while the head is torn down to replace a bad hydraulic lifter. Your help is much appreciated.

[SappySE107]

Are they the GM copper colored seats? If your heads are 00 or newer they will need to be ground out in the middle or the valve guide modified up top for them to drop in. Otherwise they drop right in and there is nothing to it really. Using those seals I would say you have the older heads that they drop right on no problem.

[DarksideGA]

my car is a 99 grand am, and the dealership didnt mention what material the shims were made of even tho i asked. but they are the stock ls1 valve seats i orderd.

[AaronGTR]

With those parts it will be a simple drop in installation. No modifications required.


And they didn't change the valve guides until the end of '00. How many times do I have to say it?

[DarksideGA]

thanks for the piece of mind, btw bitchin ga aaron. got any pix of it??

[SappySE107]

Parts book says 00-04 so id rather stick to that. Sorta like saying 94 was the first year for the 3100 when its 93.5 olds cutlass really. I would imagine you are saying late 00 based on the actual cars that got them in late 00 due to using up stock from 99 in the 00 cars. I guess looking at the valve stem seals would give it away. Older are orange, new are blue right?

[tejohnson]

The LS1 shims do work on a 99, but some clearance work May be needed. I had some slight variances on the valve guides that made me open up the ID of a few LS1 shims...

See:

http://groomlakelabs.com/?q=gallery&g2_view=core.ShowItem&g2_itemId=578&g2_page=7

&&

http://groomlakelabs.com/?q=gallery&g2_view=core.ShowItem&g2_itemId=578&g2_page=8

[AaronGTR]

Parts book says 00-04 so id rather stick to that. Sorta like saying 94 was the first year for the 3100 when its 93.5 olds cutlass really. I would imagine you are saying late 00 based on the actual cars that got them in late 00 due to using up stock from 99 in the 00 cars. I guess looking at the valve stem seals would give it away. Older are orange, new are blue right?

Yeah, thats about what I was figuring. If you go by that though that means you could have a car that's a 2000 with the correct size guides to fit the shims. Thats what I had and I bought mine new in june 2000 and it came off the line in may iirc. I didn't have to moddify anything. The shims dropped right on. My original seals (the one piece ones with the shim) where actually green.