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5.3 advice

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Old 05-13-2015, 09:04 AM
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Default 5.3 advice

I'm now putting a cam in my 2000 Silverado with the 5.3. I've got a set of cnc 243s that have been milled .030 and a 228/230 585/585 112 cam laying around.my question is is my compression going to be to low with those heads and cam?
Old 05-13-2015, 09:06 AM
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What size are the chambers on those heads? Stock 243s milled 0.030 will get you close to but just under 10:1. Your best bet is to measure the chamber volume and calculate the compression ratio.
Old 05-13-2015, 10:20 AM
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well i just put some milled .030" 799 heads on my 5.3l mind you there the same casting as 243's. before they milled them they measured 65.5cc. didn't get the measurement after milled but they take off 1cc for every .0065" milled. all the calculators put me right around 9.9:1 compression.

this is just my opinion, that cam is a little large for a 5.3l in a truck. might be fine in a light car but not in heavy truck.
Old 05-14-2015, 09:41 AM
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I guess I'll try to use my 243s get a more truck/ lower compression friendly cam . is 224 or 228 Texas speed cam a better choice for my dd.

Last edited by madracer402; 05-14-2015 at 07:58 PM.
Old 05-16-2015, 11:58 AM
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I just got my cnc 243 heads back from the machine shop. 350 @ .550 and 370 at .600 ,milled .030 and just ordered a BTR stage IV cam. Ive already have longtubes, ls7 lifters ,ls2 chain , high volume oil pump. Still not sure on head gasket size yet .. Any imput???
Old 05-16-2015, 12:05 PM
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just had tranny rebuilt and oil cooler added and plan on running a circle d stall unless anyone else has better thoughts? I know how important a good stall is but is there any ones out there alittle cheaper . Are FTI converters any good? ... Budget is way blown for my dd lol

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Old 05-16-2015, 03:42 PM
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Originally Posted by madracer402
I just got my cnc 243 heads back from the machine shop. 350 @ .550 and 370 at .600 ,milled .030 and just ordered a BTR stage IV cam. Ive already have longtubes, ls7 lifters ,ls2 chain , high volume oil pump. Still not sure on head gasket size yet .. Any imput???
just get the stock ls1 head gasket. its .051" compressed and would give you around 9.9:1 compression. the cometic .041" compressed mls gaskets would give you a 10.2:1 compression but they cost like $100 each vs the stock $35 for both from brian tooley racing.

Originally Posted by madracer402
just had tranny rebuilt and oil cooler added and plan on running a circle d stall unless anyone else has better thoughts? I know how important a good stall is but is there any ones out there alittle cheaper . Are FTI converters any good? ... Budget is way blown for my dd lol
as far as a converter i think that circle d is about as cheap as i would run. also they are like 8 miles away from me so if i don't like it i can just throw it threw their window.
Old 05-16-2015, 03:45 PM
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Originally Posted by bobfig
just get the stock ls1 head gasket. its .051" compressed and would give you around 9.9:1 compression. the cometic .041" compressed mls gaskets would give you a 10.2:1 compression but they cost like $100 each vs the stock $35 for both from brian tooley racing.
This is assuming the combustion chambers were untouched. If they were machined at all, make sure you calculate the compression based on the new chamber size.
Old 05-16-2015, 03:48 PM
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Originally Posted by Jeebalow
This is assuming the combustion chambers were untouched. If they were machined at all, make sure you calculate the compression based on the new chamber size.
true should of said that.
Old 05-16-2015, 07:19 PM
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as far as a converter i think that circle d is about as cheap as i would run. also they are like 8 miles away from me so if i don't like it i can just throw it threw their window. [/QUOTE]


That would be a pretty far throw from Nebraska for me lol ... Ive never heard anything bad about them and there performance one is only 100 more than tci ones.. My stupid *** didnt even look a btr for head gaskets when i ordered my cam..


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