I ask because besides being able to rev higher and being a little smoother its pretty much the same. I have the full fuel screw in the same spot, unsure about the idle stop screw, the high idle screw was already backed off and the linkage adjusted. If fact I actually lost boost and gained EGT, but it was about 20deg warmer and more humid out when I tested it w/ the spring. I get about 26 psi and am at about 1200 deg pre turbo in 4th gear hitting it at about 1500 and pulling to 3000. before I was at 29 psi and 1000 deg, but defueling earlier. After I bump my timing I guess its time to buy some parts, injectors, turbo...

 

I've noticed a much quicker responce when I press the go pedal other than that everything elce has been the same - egts mileage etc.

Bob

 

I didn't see any power increase. Just a better shifting tranny. With the automatic and a stock torque converter, the truck tows a lot better after I readjusted the TV cable and the TPS. ALso I noticed a snapper response when it shifts. Overall I am pleased with this mod. (especialy at highway speeds.)

 

OK, sounds like my truck acts normally w/ the spring, I read somewhere a while back how the spring made a huge difference on someone's truck, but I think they had turbo/injector upgrades.

 

It just winds up higher and feels good doing it. That qualifies as a huge difference to me.

 

I'm also running the 3k spring as well instead of the 3200rpm spring. I imagine we don't notice as much of a difference as most as we only gain 200RPM over stock. The 3200 gov spring gives 400 more RPM and is probably a more noticable difference. I'm planning to go upto the 3200,

 

I thought the 3k and 3200 were the same spring, just with different names? Aren't they both a "366" spring?

 

Should be. There are several springs that will physically fit in out pumps, but the one with 366 as the last three numbers in the part number is the most common. It's max fuel rpm is sometimes referred to as 3k, sometimes 3.2k. What it comes down to is how touchy do you want the fuel pedal to be? If you're feeling frisky, attach a piece of coathanger wire from the throttle linkage to the governor arm and remove all the AFC linkage...

 

Yep, the same thing with a different name. Mine is the 366 spring and it hit 3400 on the dyno three times. I have been told that if it goes above 3600 I will need to get 60# springs on the valves. Floating valves eats pistons.

 

Ok I have the 386 spring which is where I think I was confused, I think the 366 is the 3200 spring and the 366(which I have) is the 3000 spring........ I think.

 

As far as Im concerned there is no negatives to putting in a 3200 gov spring other then not knowing how to do it

 

386 spring = 2800 rpm. 388 stock spring is much less than that ~2400-2600rpm.

 

Hmmm, with that logic we need a 344.

 

So we can by springs in 200 rpm from stock 2400, to 3200?

 

Something like that. I wouldn't waste my time going in 200rpm incriments(sp). You don't want to be opening the pump just to try out another 200rpm. 366 and be done with it.