1961ba427

iTrader: (26)

What is the max outer valvespring diameter that fits aluminum LT1 heads without machining? I'm not saying I want to RUN the largest valvespring I can..... I just want to know what will fit.

mdacton

iTrader: (3)

1.260"

lt1-xjs

The LT4 spring is 1.320".

1961ba427

iTrader: (26)

In regards to 1.26":

I thought that was for the iron heads....and for LS1's. Don't the Crane 10308's fit without cutting the spring seats? They are 1.46" from what I've read.

1961ba427

iTrader: (26)

Anyone else?

guppymech

iTrader: (7)

The stock spring locator measures 1.300 OD. I just looked at a spare head I have and with the contours of the head casting and the machining of the spring seat area there isn't alot of room to go a much bigger spring locator. I just bought some PAC LT4 type drop in springs (1212X) that measure 1.355 OD. I haven't got them yet but they should fit fine.

Puck

iTrader: (17)

Crane 10308s fit fine, and come with their own shims.

They are 1.46" as stated.

RamAir95TA

iTrader: (2)

I used these for 5 years. Work great in the stock pockets.

Just remember the 10308 is the p/n for the spring and hardware kit. The springs themselves are p/n 99893 (if you wanted to use your own hardware).

Puck

iTrader: (17)

Good point about using your own hardware. I used the kit successfully for a couple years in a daily driver, but wasn't too impressed with the shims it comes with. They are literally just shims, not proper locators.

Probably not a big deal for the type of builds that will be using them, but worth mentioning.

1961ba427

iTrader: (26)

So......is 1.46" the biggest that fits orr is it just largest OD ya'll have used and know is a bolt-in?

BTW, I've been running the #10308 kit for about a year now and I'm pleased with it. I'm just shopping around for some other builds. I also know the old standby answer: Run the springs your cam grinder recommends.