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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: emr_09 on November 10, 2009, 07:29:38 pm
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Well after spending too much on my engine already I'm not happy with the performance. Heres what I have that I can remember. 350 block bored 30 over, scat stroker crank, 5.7 rods, speed pro hyperneutic pistons (cant remember what), vortec heads, mild crane cam, professional products intake and 600 edelbrock carb with k&n air cleaner. I had it balanced at a race shop. Everything else is pretty much stock. I want something that will flat out get it when you stomp on it. Any suggestions? I'm looking at different heads, rods, pistons, roller cam, roller rockers intake, carb, and possibly a converter (suggestions?) and a built 350t to put behind it. I'm just not sure what combination to put together. I don't want to overdue the cam to where it wont run at an idle.
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Properly tuned, that thing should work pretty well. What gears do you have & how big are the tires? Lorne
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3.42s with 31x10.5s. Thats prlly not helping to much. Im trying to find a set of 3.73s but not having very good luck.
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Don't go throwing more parts at it yet. Maximize your current combination first, it sounds like a good one.
What is your exhaust system? Is it stock? That would not be appropriate for this engine. You should have long tube headers and a true dual 2.5" with high flow mufflers. Check out this (http://store.73-87chevytrucks.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=7&Product_Code=SGT80&Category_Code=73-87UHood) system that Chris sells; that would be an excellent choice when paired with Pypes Race Flo, Dynomax Ultraflow, or Magnaflow mufflers.
Is your ignition timing dialed in? Vortecs, based on what I know, tend to want only 32-34 total timing. Play with your initial and the rate of the curve and see what your truck likes.
Another guess is you don't have your carb dialed in. I would buy a kit like this (http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=FS&Product_Code=170634&Category_Code=AnalogAFGaugeKit). Use it to dial in your A/F ratio to 12.8:1 - 13:1 at WOT and reveal lean spots at part throttle and transition. Eddy's are pretty easy to tune. Although I'd say that a well tuned 750 Holley vacuum secondary would probably offer better performance on nearly any street 383.
Another suggestion: You may be the kind of guy who needs a hot big block to "flat out get it when you stomp on it."
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Eventhorizon makes a lot of sense. Exhaust is very important. When i put my 383 in, i went with duals w/ new cats...no muffler, stock exh manifolds though. But, with my old clogged cat and exhaust, I wouldn't get anywhere near the performance i get right now.
Ensure your carb is dialed in and timing.
3.42's with 31's makes for a semi-tall rear ratio, not the best for 'from-standstill' wiplash action. Not a bad set up for a built 383 for some fun. It's a middle of the road gear setup.
I want something that will flat out get it when you stomp on it. Any suggestions?
That's is subjective, but, I must tell you, my 383 edelbrock carbed, th350c tranny and stock 3.08 rear and tires hauls but! And, on the interstate, nothing touches me if I put my foot down. If I had a 3.73 or lower gear, I wouldn't be able to keep tires on it.
The specs for my 383 are on this (http://www.delbridge.net/install) site. Nothing fancy, but loads of torque and w/ an RV cam, she takes advantage of lower rpm's, which is great for my higher rear ratio.
Depending on what you mean by the quote cited above, Eventhorizon is right, perhaps a big block is what you are looking for.
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^ Agreed. What specs exactly are your mild Crane cam?
With my setup in my sig below, on 27" tall tires and a 3.40 ratio, I'm wanting more, like a 3.73. 31" tall tires should definitely go with a 3.73.
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Ive cant find my receipts from when I built the engine. I have new exhaust from the manifolds back with 2 1/2" piple running true duals out the back with flo-pro turbo mufflers. The cam is mild enough where it has a slight lope at an idle. Thats all I can tell you right now until I find the receipts. Thanks for the input guys!
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definately a set of long tube headers would benifit the cause. since having a stroker id mite change to a bigger cfm carb.say 750. i prefer hollys but utimatly up to you. what kind of intake manifold are you running. if a dual plane try putting a 1 inch open spacer underneath the carb, 20 some bucks and i noticed a difference on my truck.
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I would seriously consider some 1 5/8" primary long tubes. Properly sized headers can be worth 10-20 ft-lbs throughout the power band on a stock 350. But the gains will be even greater for a 383 with good heads and larger than stock cam.
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Well after spending too much on my engine already I'm not happy with the performance. Heres what I have that I can remember. 350 block bored 30 over, scat stroker crank, 5.7 rods, speed pro hyperneutic pistons (cant remember what), vortec heads, mild crane cam, professional products intake and 600 edelbrock carb with k&n air cleaner. I had it balanced at a race shop. Everything else is pretty much stock. I want something that will flat out get it when you stomp on it. Any suggestions? I'm looking at different heads, rods, pistons, roller cam, roller rockers intake, carb, and possibly a converter (suggestions?) and a built 350t to put behind it. I'm just not sure what combination to put together. I don't want to overdue the cam to where it wont run at an idle.
what the CR ratio?
cam shaft specs
exhaust?
3.42 with 31" tires
what the intake manifold? OEM replacment or a nice high rise dual plane?
mine you a 383 likes to breath!
what is the TC stall? 2,000 stall would work nicely 2400 woudl move out more but hurt cruising MPG