Picking a cam/rebuild advice for 350 in 84 c1500

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Honky Kong jr

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You could find a good used 454 and rock that till you can rebuild it and have a more noticeable difference then a cam swap in a small block. And go Th400 or rebuild the Th350
 

crazy4offroad

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I'm in the middle of a similar rebuild myself, except I won't be having the block bored. Mine is in pretty decent shape, no ridge ring and fairly good on out-of-round/out-of-taper spec, standard bore. I think a quick run-through with a hone will give it some cross-hatch. My parts list so far:

Comp 268H square pattern cam, lifters and timing set, $217
https://www.summitracing.com/parts/cca-sk12-210-2

KB Claimer +7cc flattops with rings & wrist pins, $249
https://www.summitracing.com/parts/uem-9901hcktmstd

0.028" compressed thickness head gaskets, around $70/pair
https://www.summitracing.com/parts/nal-14096405

With a pair of craigslist Vortec heads I picked up a few years ago for $250 and had the local machine shop do a 3 angle valve grind, decked and hot tanked with new springs and keepers for $300, I'm expecting in the neighborhood of 10:1 compression ratio or just under. The cam I picked will work with Vortec heads lift limitations. And even though Rusty Nail may sound like a nut, I'll be opening up the top ring gap to 0.030" and the 2nd ring gap to 0.035" just incase I want to add some giggle gas down the road. I already picked up some items but plan on replacing the water pump, oil pump and fuel pump, as well as a reman crank. Upon inspection/measuring if the crank is OK it may just get crank and rod bearings and save around $100. As for the trans, I rebuilt it a couple years ago, performing several mods that should help it sustain into the 500hp range, setting it up for dual-feed, increased the line pressure a little and dropped out the check balls for harder hitting shifts (something you may not want, it hits HARD). For a converter I've been eyeballing Summit's 2000-2400 stall at $230:
https://www.summitracing.com/parts/sum-g2700-1
Should work good with the cam's powerband. I'm hoping this setup will keep me in Street Class at the mud races but may end up in Hot Street if it won't hold at least 17" of vacuum. With no class limitations other than "6 cylinder" and "V-8" for the additional Hill-And-Hole competition, a 100hp or so shot of nitrous should make for interesting launches off the jumps. If you didn't want to bother with trying to find a good set of Vortec heads (since they're susceptible to cracks) Summit sells a nice set of Vortecs that have great reviews, and able to handle up to 0.520" lift:
https://www.summitracing.com/parts/sum-151124
Hopefully all this will give you some things to think about and compare. I'm hoping to have it reeled in for around $1500.
 

bman1985

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@crazy4offroad sound like a very similar build. I saw that comp 268 cam mentioned a lot online, I was wondering how it would be. I know nothing about choosing cams so let me know how that works.

Those summit vortecs look like a good deal, they already have screw in studs and can take higher lift. Hardly save money buying used and getting them machined.

From the looks of things I might be better of time/money wise just getting a newer l31 vortec 350 from the junk yard and putting in a cam vs rebuilding my motor. This truck isn't my daily driver so putting in a motor with 100k isnt a big deal.
 

RustyPile

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I've built numerous 383s for race and street applications, dating back to the days when the sbc 400 was still in production.. One thing that hasn't been mentioned about cam duration as it pertains to torque converter requirements.. Given the same cam specs, as engine displacement goes up, the "tighter" a torque converter can be.. You put that Comp Cams 268H in a 350 and you'll need a higher stall converter.. Put it in a 383 and a stock converter works just fine..

Build a 383 using 5.7 rods.. The extra rod length just adds to the torque numbers. Vortec heads will be a bolt on without modifying for higher lift, just watch the compression ratio and select proper pistons... At .454 lift, you're .020 to the good with the vortecs.. A 383 built right is a small block that thinks it's a big block..
 

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