73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Performance => Topic started by: 355shortbed on January 09, 2009, 01:03:21 am
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Has anyone de-stroked a 350? If so what did you do , how did it work out, how did it run? i have a 355 freshly machined and a 327 i was going to build for my isuzu pick up but, money is getting low. If i was to put put the rods from the 327 in the 350 it would basically be a 327 but in a four bolt main block, would it be any point?? well thanx for any thoughts just wondering
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hahaha srry about the poll , its late, i just got off. just ignore it ;D ;
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If I'm not mistaken, I think you'd need the crank as well as the rods from the 327 so that the pistons come up to TDC correctly with the shorter throw of the 327 short-stroke crank. What you would be accomplishing is generally a higher-RPM capability at the expense of low end torque. If you want a real HP screamer and not a TQ monster, then a 327 can help do that. Sorta the opposite philosophy of why people go for 383 strokers. Nuthin' like the sound of a SBC at 7000 RPM though :) What kind of heads and cam are you planning?
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I would stick to the 355 combo the 327 and the 350 have the same bore(4.00) and the same rod(5.7) the difference is the crank 327=3.25 stroke and the 350 = 3.48 stroke. But the kicker is that early 60's 327's have a small journal mains and late 60's have a large journal(same as 350). here is a list from www.mortec.com of Small block bore and stroke info. Hope this helps..
262 = 3.671" x 3.10" (Gen. I, 5.7" rod)
265 = 3.750" x 3.00" ('55-'57 Gen.I, 5.7" rod)
265 = 3.750" x 3.00" ('94-'96 Gen.II, 4.3 liter V-8 "L99", 5.94" rod)
267 = 3.500" x 3.48" (Gen.I, 5.7" rod)
283 = 3.875" x 3.00" (Gen.I, 5.7" rod)
293 = 3.779" x 3.27" ('99-later, Gen.III, "LR4" 4.8 Liter Vortec, 6.278" rod)
302 = 4.000" x 3.00" (Gen.I, 5.7" rod)
305 = 3.736" x 3.48" (Gen.I, 5.7" rod)
307 = 3.875" x 3.25" (Gen.I, 5.7" rod)
325 = 3.779" x 3.622" ('99-later, Gen.III, "LM7", "LS4 front wheel drive V-8" 5.3 Liter Vortec, 6.098" rod)
327 = 4.000" x 3.25" (Gen.I, 5.7" rod)
345 = 3.893" x 3.622" ('97-later, Gen.III, "LS1", 6.098" rod)
350 = 4.000" x 3.48" (Gen.I, 5.7" rod)
350 = 4.000" x 3.48" ('96-'01, Gen. I, Vortec, 5.7" rod)
350 = 3.900" x 3.66" ('89-'95, "LT5", in "ZR1" Corvette 32-valve DOHC, 5.74" rod)
364 = 4.000" x 3.622" ('99-later, Gen.III, "LS2", "LQ4" 6.0 Liter Vortec, 6.098" rod)
376 = 4.065" x 3.622" (2007-later, Gen. IV, "L92", Cadillac Escalade, GMC Yukon)
383 = 4.000" x 3.80" ('00, "HT 383", Gen.I truck crate motor, 5.7" rod)
400 = 4.125" x 3.75" (Gen.I, 5.565" rod)
427 = 4.125" x 4.00" (2006 Gen.IV, LS7 SBC, titanium rods)
Two common, non-factory smallblock combinations:
377 = 4.155" x 3.48" (5.7" or 6.00" rod)
400 block and a 350 crank with "spacer" main bearings
383 = 4.030" x 3.75" (5.565" or 5.7" or 6.0" rod)
350 block and a 400 crank, main bearing crank journals
cut to 350 size
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well i dont know what i want to do with the heads, i have the fuelie double hump heads that came w the 327, oh its a late model i think a 1968, but i have a set of regular truck heads that i did a little work to smoothing the ports and runners down, a small valve job and also had machined for screw in rocker studs for rollers. Being as the fuelie heads dont have accessory bolt holes i might not use them. i just want somthing fun to stick in my old four speed k10 thats not just a regular small block. I have a new cam that was for the 355, its a crane energize 3/4 race cam i think advertise duration is 274 @ 450 intake and 450 exhaust lifts, 106 Lca. but not sure if thats what i want to put in it becuase i want a loapy idle and dont konw if that will give me what im lookin for
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327 and 350 may have 5.7 rods and 4" bore but the pistons im prettu sure are different because the compression distance would be far off. if the rods dont change during the stroke, the pistons must
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Cubic & Dan is correct....All of the "normal" small blocks have 5.7" rods except the 400. To do what 355shortbed is talking. You have to have a matching crank/block (both small or large journal) & 5.7" rods & pistons from the 327 (or of that compression hight), so what you end up with "de-stroking" a 350 (using the stock configuration) is a 327. You can look at it like a 327 was "stroked" to be a 350 originally. Lorne
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yea i got all the pieces from crank to pistons, and luckly enough both blocks have been bored 30 over and have new pistons, thanx for all the answers guys
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you can do it but you`ll need the crank and pistons for a 327. You also have to make sure the 327 crank is from a 1968-1969 engine or a later model 307 which shares the same stroke as the 327. The pre 68 327`s have a small journal crank and won`t fit the large journal 350 blocks.
I agree to leave it a 355. 327`s are my fav but in these heav trucks you need al the torque you can get.
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You can do it, but there is no substitution for Cubic inches.
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There's no replacement for displacement ;D
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just a quick question y would some one wanna destroke a motor? never heard of it till now
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In theory, a destroker screams! Look at the chevy 302s, 4" bore and 3" stroke (327 block, 283 crank). those motors ran 9 grand all day! Now granted I think they topped the chart at around 150 ft lbs :D but nothing a set of 5.13 gears couldnt help! ;D
Dirt track guys have been destroking 400s for years. 377s (400 block, 350 crank) make some revs too!
But in the end, as the old saying goes, "There is no replacement for displacement!"
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No matter what the stroke, when rpms go way up, either cost goes way up too (4340 cranks, h-beam rods, etc) or durability goes way down. Larger engines make more power in a more reasonable rpm range and at a lower cost.
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c thats what i thought. iv only ever heard of stroking an engine. buddy of mine just built a 383 stroker for his 86 c10. so what you kinda saying is a destroked motor is more for high rpms like in racing applications?
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The bigger stroke will make serious low end grunt while destroking will push the powerband higher up in the revs. Trying to keep this as clean as possible, think of it like this. Take a hand saw with a wicked set of teeth, you can saw through a limb pretty easy if you put some muscle behind it (stroker). Next example, take a sawzall and turn it wide open (destroker). Both cut the limb, the hand saw was brutal, took like 5 strokes while the sawzall took the same time but turned severall more revs.
??? ??? ???
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excellent point. i like that!! I believe im going to destroke it because it will be going in a small 93 isuzu pick up where torque really wont matter :).
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There's no replacement for displacement ;D
pop quiz: who was credited with coming up with that saying?
Answer is: Walter Bentley, founder of Bentley motor company
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I've bounced around the idea of building an s10 for the street and with the lightweight of the truck, huge amounts of torque off the line will just shred the tires. if you push your power higher in the band, the truck will scream on top end. then you can match your gear set to what you need as well as a stall converter. Build the motor for max HP and forget about an torque numbers. Make up the torque in reduction via gearbox and rear axle.