Vortec Rebuild

[speedshifter]

Hey guys,

 

planning to rebuild my '97 vortec 350 in my yukon.  I have a '93 shortblock with only 7,000 miles on it.  will that work as a direct replacement?  if not, i will have to rebuild my 138k mile motor.

 

im looking to do a cam, roller rockers, ported/polished/machined stock heads, k&n intake, full stainless exhaust (edelbrock headers & y pipe, catco cats, gibson catback)

 

also gonna do a hypertech programmer in there too.  my goal is 300rwhp and gobs of torque

[americanmuscleman]

The 93' block will have a different compression ratio.  A 93' block will also use a hydraulic cam rather than a hydraulic roller cam like the Vortec blocks.  You can put a roller cam in a non-roller block.  You will have to use a roller timing chain, crank sprocket and cam sprocket, put in roller lifters and a lifter valley retainer (probably could both be pirated from the Vortec), and you'll need different pushrods.  I'm using 7.3" ones in my roller TBI.

 

Its going to take a fairly stout cam to make 300rwhp, and that power is going to likely come at over 5500rpm.  By going to bigger cam, your going to trade low end power for midrange and top end power.  Porting your heads and putting in a bigger cam really changes the driveablility of your truck.  You'll also probably want to change your torque converter to a little looser one, otherwise your truck is going to surge in gear.  Your gas mileage is also going to drop more as you go to a more aggressive cam.  

 

If I were you, I would take your TBI block, assuming it will work fine in your truck, and put a stout bottom end on it (forged pistons, nice crank, good rods, good bearings), mild roller cam like the LT4 cam, port the heads, and put a blower on it.  It will get you your 300rwhp goal, gobs of torque, and still have stout low end power, good driveablility, and decent gas mileage.  

 

Just my 2 cents.

[americanmuscleman]

Also, if you do big mods like port your heads or put a different cam in, your going to want better tuning than a hypertech can offer.  I would check out PCMForLess (www.pcmforless.com) or Ed Wright (www.fastchips.com) for tuning.  I'm using a chip burned by In-Tech (Innovative Technologies) out of Fresno, CA.  Your computer uses a flashable memory, so there isn't a chip to replace (which is a good thing).  

 

You can get a cable that plugs into your diagnostic port under your dash, and load your programming in there (just like a hypertech).  You'll need a laptop, but Ed or Bryan at PCMForLess can create tuning for your truck that will self-load off a laptop into your computer.  They can send you your tuning via email (what I do).  Its really slick.  If you want to know more about that, let me know.  You can get a cable that connects your computer to your diagnostic port from AKM Cables (www.akmcables.com).