Engine/Transmission (1994 - 1998) gsk questions for 72 chevy 12V conversion

[BCronk]

Some one explain what you gain with with the 3000, 4000 governor spring kit. Is gsk a governor spring kit? I am new and haven't figured out all the lingo yet. Anyway I have a 72 chevy 4X4 I put a 94 cummins in, It takes off like a rocket but loses all its power around maybe 2000-2500. I say maybe 2000-2500 since I don't have a tach yet. Also I checked my rpms at wot in park with one of those pointer tach reader things and got almost 3000 rpm. I know I am not hitting 3000 on the highway cause I cant get over 80 mph. I have 3. 07 gears 35" tires no over drive no lockup convertor, I should go over 100 mph with this set up. What I want is more top end speed & more high rpm power. I know I need an OD trans but will a 3000, 4000 gsk get me by for now? Any help would be appreciated.

 

[Berrigan]

Welcome to the TDR. Yes a gsk is a governor spring kit. If your 94 is stock it will rev to 2700 to 3000 in neutral but under load a bit less. Your rpm tests and speed calcs sound about right for stock. Your truck starts to de-fuel at about 2400 to 2500 rpm. A 3k gsk will allow full fueling to about 3200 rpm. It will make a huge improvement in higher rpm power and will improve top end speed. Be carefull, stock you cant over rev it, with a gsk you can. Stock valve springs are good only to about 3300 to 3400 rpms. If you replace the valve springs with stronger springs you could go with the 4k gsk. Most folks seem to go with the 3k. I rev mine to 3300 and dont feel comfortable going any higher. Bill

 

[Berrigan]

By the way you should probably get an accurate tach so you know where you stand. You sure dont want your valves kissing your pistons. Bill

 

[Cooker]

Every truck needs a GSK.



Stock defueling can begin as early as 2100-2200RPM's



A GSK will help with upper end performance as well as better all around driveability.



A with the 4k you can get a little bit of a sensitive throttle and you may feel the loss of a little bottom end over the 3k.



BTW - Welcome to the TDR.