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Old 12-08-2010, 02:06 PM   #1
81ShrtBox
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Location: Hammond, La.
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Help/Input needed

I recently did a Vortec swap in my 81" Shortbox.

99" yukon heads on a 96" suburban block(heads decked, valves polished, new seats, lil-pocket port clean up)
Beehive springs
Will Hoites 270 Roller cam .495 intake .218@50 and .502 exhaust .224@50
thin head gaskets
Headers
Summit Race mufflers with 2.5" pipe slight angle before rear end
KMJ Performance 65,000volt HEI distributer
Edlebrock 750 vac sec
ebay Performer RPM replica intake


trucks drives and runs great, the Will Hoite camshaft sounds mean as hell. But when I get on the gas it jumps forward then falls on its face... does a means burnout... just cant get the dam thing to perform.

It acted better after I replaced the stock distributer, but still isnt 100%. I'm changing the fuel pump, and then the roller lifters are next( I re-used the old ones). I have tried changing to platinum plugs, carb is like new... even checked to make sure I had 12v to the coil...I'll try changing the alternator because i want everything new anyway... if the fuel pump and alternator dont change the problem I'm yanking the engine and starting over with another combination...

This one will be Competition Cams, MSD Electronics and an Edelbrock intake... I looked at alot of different reviews with people having excellent results with this same combo(est400hp/380-400ftlb torque... but its giving me the blues

Last edited by 81ShrtBox; 12-08-2010 at 02:18 PM.
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Old 12-09-2010, 01:10 AM   #2
Captainfab
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Re: Help/Input needed

Have you set your total timing? Where is it at? What do your plugs look like? Did you make sure there is sufficient retainer to valve guide seal clearance?
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Old 12-09-2010, 09:26 AM   #3
swb85
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Re: Help/Input needed

If you slowly roll into the throttle instead of smashing it does it still fall on it's face?
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Old 12-09-2010, 04:50 PM   #4
81ShrtBox
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Re: Help/Input needed

Quote:
Originally Posted by Captainfab View Post
Have you set your total timing? Where is it at? What do your plugs look like? Did you make sure there is sufficient retainer to valve guide seal clearance?
Plugs looked good(one had fouled and was wet from the carb not being set right), the retainers-springs I used were supposed to be drop in installation. GM Vette Z06 beehives from summit with Comp Cams retainers... simple drop in installation. A buddy of mine is a ASE Certified Technician.. he set and double checked my timing... told me dont touch it.





Quote:
Originally Posted by swb85 View Post
If you slowly roll into the throttle instead of smashing it does it still fall on it's face?
If it slowly roll on the throttle it still breaks up around 4-5,000 rpm..
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