Engine/Transmission (1994 - 1998) Does a 4K GSK really rev to 4K?

[JBlackwell]

Just wondering, I might not have them set right. I know I got both springs set identical... . think it was . 042 but it was a while back. Just noticed it today that it will rev to 3400 in 4th gear and stop. Check sig for mods. You think something is up for do I need to go and recheck the tolerences? I was thinking that I could get 3750rpms out of them.





Justin

 

[MDW]

The 4K spring kit allows for the "possibility" for 4000 rpms but your pump isnt likely to get there without a lot more timing.

Adding that much timing can cause other problems, such as blown head gaskets.

 

[JBlackwell]

The 4K spring kit allows for the "possibility" for 4000 rpms but your pump isnt likely to get there without a lot more timing.

Adding that much timing can cause other problems, such as blown head gaskets.

Ahhh, so with my timing and mods, 3400 is about the highest rpm everyone else sees?

And if so, how much timing would I need to get 3800+rpms? I won't do it, just wondering.

 

[TReed]

I can tell you with my mods. and with a auto when pulling sled my truck hits 3600 rpm and thats when I shift into 2nd and then hold 2nd gear 4000rpm the rest of the way down the track with no problems.



Travis

 

[98slushbox]

from what i've seen, a 215 gets to 4k with ease, but a 160 has a little trouble getting there. I can only get mine to about 3700 with my upgrades. What does your trucks idle at? I've got mine at about 7 or 800rpms. If it idles a bit lower, the springs may be the same but both could be turned down a click. just a thought

 

[JBlackwell]

Well, I have the 175 pump w/ stock DV's so that also might be a reason or part of the reason. Another thing I was thinking about last night is that I have a #10 plate slid up about . 120 and that may be so far up it is defueling. Might not be, but I am going to slide it back and see what it does. Wish I had a #0 plate... ... ... Oo.





Justin

 

[98slushbox]

Justin,

You could take your stock plate and grind it to a 0. Dont know if the plate thing will help or not for rpms. I would think a 215 pump with a 4gsk would run 4000 with any plate in it. But i am just assuming.

 

[Jim Fulmer]

I would think a pump with a 4gsk would run 4000 with any plate in it. But i am just assuming.



The only pump(in stock form) I've ever seen that could make 4K or close to it with a 4K kit is a 215 pump, I do believe that a 160,175 or 180 pump all need a 4K kit(just and opinion) and a 215 if you are high (over 500) in the HP game, also remember there is a difference between making 4K and pulling to 4K and I know of no stock pump that will pull to 4K.



Jim

 

[JBlackwell]

98slushbox: Yeah I want to make a #0 out of my stock plate, but I can't find the dang thing. I was so hiped about putting the #10 in that I just threw the stock plate over my shoulder when I took it out. LOL I have been looking for it. I want to run the truck over to a dyno and see what it can do with stock DV's, but I want a #0 and don't want to take the plate completely out.



I wonder if I can hit 450rwhp with a #0 Oo.

Or do I need to go 191 DV's to do it?





Justin

 

[JJW_ND]

215 = well past 4000

I think the pump (160 - 175 - 180 - 215) has the most to do with the RPMS the GSK kits will provide. Only having a 215 pump, I am guess the rpms will be higher the higher HP your pump was from the factory with the 215 pump in a league of its own.



I had 3GSK in for a while. Could rev to 3400 and pull trailers to that RPM. Thought I need more and put in the 4 GSKs. Becuase I did not add any more air, no head work, I did increase timing, all I got was high EGTs and smoke above 3K. I got very nervous with others driving my truck as it would rev right past 4000. I never pushed to see how high but was told most 215 will do around 4400.



I pulled the 4 GSKs.



jjw

ND

 

[98slushbox]

Fulmer,

I agree with the differ. pulling to 4k and just reving to it. Mine doesnt fuel near to 4000, well I cant even get it to rev there either, but it doesnt fuel near that far, but if i hold it there it gets to about 3700. It quits pulling in the lower 3000 range.

 

[Jim Fulmer]

Some people view pulling at high RPM a little different as do I, I view mine as pulling in O/D..... cool but scary, I do know the pump doesn't get fuel break away till 2500 pump or 5000 engine.



Jim