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I have a 98 form 3 700, w/ stock mach center dumps. As posted eariler, I can not get it to pull past 90mph. Tach "says" 8000. It has a 200-280 primary, and belt gets very hot. Should I use the 230-320 mach spring? That seems it would make less side pressure = hotter belt? Also Ive head many bad things about the center dumps, but if you get em hot, they produce more tourque than end outlets, but less top hp. Would it be worth going w/99 up pipes? I still think yhe problem is in clutching. Any Ideas.

Also, the front suspension rides horrible. I plan on rebuilding shckes, they are t/a, but have the 85lb springs 315mm long. I was thinking of maybe 120lbs @ 265mm. Any one have any luck with changing spring rates? It has sc-10 III. Thanks
 

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Make sure and check engine alignment. You should be carrying about 21-24lbs on secondary. With the belt getting
hot it sounds like it is slipping. I personally have a 280/420
primary spring with stock pins on 286 ramps. Mine will pull past the 90 mark without to much trouble.
 

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do like drsting said, check engine alignment.      had a 98F-III that did the same thing, engine was out of line and the clutchs were worn out(13 000 klm)        how many grams of pin weight are you running, and are they stock arms?
 

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1000IMP, and Drsting, are exactly correct.   Stock setup, you need at least 21-24 lbs. on the secondary spring, in fact if it is old, replace the secondary spring, realign the clutches, add a new belt if worn, and set your clicker on #2 and test and tune from there.   The 98 Mach 1's were quick, make sure your pipes are "hot" also, they perform the best when they are warmed up.
 
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