i have a stock 89 GTA 5.7L and i was wondering if anyone knew how much horsepower that block could take? Im thinking of rebuilding soon and i want to know what it can handle. Or if i should even keep that block.

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Later,
Vomex
'89 GTA 5.7L TPI

 

Vomex,

The general concensus is that a stock cast crank and rods shouldn't be used for engines running over 425-450 HP at the crank. There are even some variables with those conditions, but generally those are the accepted limits.

Anything running over 450 should have four bolt main caps, at least a nodular iron crank, and should have improved con rods. It is possible to clean up the cast rods and stress relieve them, clean up the casting imperfections and lighten and balance the cast crank, and stud the two bolt caps enough to probably run over 450 without failure, btu you're on the ragged edge if the RPMs start to float up on you. And 450 isn't difficult if you plan well.

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Later,
Vader
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Justice and Freedom will Prevail

 

Speaking of planning well, is there a good book on engine rebuilds and mods? I want to plan my engine out well and i would like to get as much info as i can before i start.

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Later,
Vomex
'89 GTA 5.7L TPI