604 Conversion kits are available

[brad hibbard]

Most GM Performance Parts dealers now have the new 604 conversion kit in stock

check your local dealer for GM# 19300952

we have plenty in stock if you can't find them but you should be able to avoid shipping costs by making the purchase locally.

the kit fits perfectly and looks like very durable stuff-----should be bonus to crate racing

Brad

https://www.race-1.com

[mickeyd18]

How much do the kit cost and should it be done to a brand new 604 that has the old type springs

[Egoracing]

Has GM released the new installed height?

[Matt49]

What is the retail price on this part number SUPPOSED to be?

[stockcar5]

According to Hendren no heights are listed yet. The best price I found with a quick google search was $240 via gmpartsdirect.com

[Egoracing]

That is the same info I have heard form others, but the installed height is supposed to be out soon. Would be good info to know before installing a set.

[brad hibbard]

working on all this now
stay tuned

Brad

[Race Dog]

Same Spring as the LS6 here is some info on the spring I'm sure the installed height will not change from 1.780
12625033
valve springs (not shown)
Beehive style springs
Standard LS6/LS3 springs
1.250" @295 lbs.
1.800" installed height @90lbs.

[Egoracing]

1.780 would get you DQ'd. This is straight from NESMITH Racing.

Installed Height (Ok to shim to proper height) 1.800″
Pressure @ Installed Height (+/- 5 lbs) 90 lbs.
Open Height 1.300″
Open Pressure (+/- 13 lbs) 264 lbs.

http://www.nesmithracing.com/604-valve-spring-technical-bulletin-update/

[Race Dog]

Went from 110 +/- 5lbs to 90 +/- 5lbs on installed height pressure.
Can we say backed up or what ?
Open went from 270 +/- 10lbs to 264 +/- 13lbs
One would think they would have the same pressure not less ?
maybe the Beehive style are magic who knows
Happy Racing

[Racer63]

Did you read the Nesmith update. I'm no engine guy but it says the springs will be about the same being they are a beehive style. Theyre the same thing as they run on the 525 so they can't be that bad right????

[brad hibbard]

in response to installed height:

From GM and all sanctions I have checked with
installed height is 1.780
seat pressure @ installed height is 98 +or- 4.5lbs (Nesmith 5lbs.)
open pressure @ 1.300 is 267lbs. +or- 13lbs (Nesmith 264lbs +or- 13lbs.)