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lt4 hot cam install, 98 L31 350 5.7 4boltm crate enigne help
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Post lt4 hot cam install, 98 L31 350 5.7 4boltm crate enigne help 
I'm looking for more performance out of my truck and I've seen forums and pictures of it done before WITH OUT machine work being done to the stock heads but i don't know what to order for it to be able to do it and have it done, i already have a 2500 stall torque converter and a stage the shift kit with the intermediate band in my 4l60e and i have the vmaxx air intake spacer along with a throttle body spacer and an 80mm bbk power plus throttle body and cold air intake and a true dual flow master 2.5 inch exhaust and a ported stock mass air flow sensor, can any one send me a link or list of parts needed to do the lt4 cam please

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For the oem heads

It would be very tight to do the Lt4 + 1.6 RR and just keepers and retainers.
Probably LT4 cam + 1.5 is doable

You need to use a dial indicator to verify the stroke that you have now
(Make sure the seals are tapped all the way down but don't tap too hard or you'll damage them)
And then you can add to that the extra travel from the new keepers and retainers.

If you were to do this mod, I wouldn't bother with machining boss guides, just pin the rocker studs

The lt4 has .525 lift with 1.6rr but .492 with 1.5rr

That extra lift won't do much cause the vortec don't flow much more past .500

Hope this helps, will add more details when i have a chance this weekend

If you have the cash, AFR heads are the way to go

http://www.airflowresearch.com/190cc-sbc-vortec-cylinder-head/

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Lots of info here:

http://www.crankshaftcoalition.com/wiki/Vortec_L31_cylinder_head

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Chevrolet recommends using the Crane Cam p/n 10309-1 drop-in valve spring/retainer kit which is good for 0.550” lift (this allows about 0.025" between the retainer and seal) with no machining. The spring rate for this spring is 409 lb/in and has a 0.870" ID.

When retaining the factory boss and seals, be sure the valve seals are driven on all the way. You need to check that they are before installing this kit. Use a 3/8” drive 1/2” socket and a soft mallet to gently drive the seals fully home.

https://m.summitracing.com/parts/crn-10309-1

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Ask this guy. He just did his

http://www.pacificp.com/forum/viewtopic.php?t=14339

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From Pirate 4x4

787-16 comp cams retainers
Comp Cams 648-16 Locks
Comp Cams 26918-16 Springs

And you should be good for 560 lift... without any machine work involved.:smokin:

Edit: You will ALSO HAVE TO Drill the push rod holes in your heads with a 1/2 inch drill bit,

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http://www.powerperformancenews.com/tech-articles/installs-and-builds/budget-vortec-head-upgrade-easy-money-saving-benchtop-mods/

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Comp cam Beehive springs 26915 or 26918 

Comp cams 787 retainers 

Comp cams 648 keepers. 


That combination adds 0.050" more lift over the OEM retainers and locks

So, tap your seals down and add 0.050" to watever valve travel you have now, and you'll know if you can run the LT4 cam

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