what can i expect from my 360?

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dustinmoran91

dustinmoran91

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Thia is my first thread so please be gentle lol I have a 73' 360 block and crank that are at the machine shop getting worked over. Theyve been there over two months sadly for basic work. Im runnin stock crank and rods with keith black 191 pistons in a .060 overbore so the specs are as follows. 12.5:1 compression or close atleast. Minimum .500" lift cam with no more than .300 durarion advertised of course lol either magnum heads ported and flowing as good as possible or 915's ported. I havent chosen yet. And a proffesional products air gap intake fed by an 850 demon converted over to e85. Hoping for close to 500hp at the crank
 
Well, shooting from the hip on all the parts you selected, your sure to have some idea, right? That's about what you'll get this side of a dyno. Lots of factors, and speculation.

There is a cam selection/hp estimation program available on the comp cams website, its called CamQuest.

Hope this helps.
 
dustinmoran91 said:
..............or close atleast............. Minimum .500" lift cam with no more than .300 durarion advertised.....................flowing as good as possible..............
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Lotta variables there. Narrow it down with some specifics and we can come close.
 
Here is an old school build up dyno'd that should about meet your level. Due note the comp ratio is a 10-1 vs. your much higher targeted ratio.


360 rebuilt with 10:1 compression flat top cast pistons, original crank turned .010"/.010", rebuilt factory rods. Factory windage tray installed. 2.02" heads with competition valve job and ported to flow 260 cfm. Edelbrock RPM intake, port/gasket matched. Holley H.P. 750 (.076" front, .080" rear jets). Large 1 3/4" primary tube headers. Comp Cams 305AH-8 camshaft with .525"/.540" lift and 305/312 degree advertised duration, 253/260 degrees @ .050", 110 lsa, installed at 108 intake centerline. This motor is a brute for a street car and would only be considered a weekend blaster.
495 h.p. @ 6,000 rpm
500 lbs. of torque @ 4,500 rpm
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Taking a look at your build, I think you'll make it. I myself would not use a Magnum head. For an iron head, it would be the W2 or LP Commando, and in aluminum it would be Edelbrock heads. All heads would need some work done. OE heads would need the full porting plus. I do not know if it is worth it at that point to due the OE head.
 
Ehh, it was just an example. His combo has more compression but runs less powerful E-85 and another 100 cfm on a great carb. I can not compare the RPM to the knock off, I have no data.
He may yet very well get away with a smaller cam depending on the head used and how well ported it is.
 
thanks guys! im very appreciative for all of your answers. im wanting to stick with a production head to save money for the time being. i was considering the magnums because of the 1.6 rockers and the better flow than an LA head straight from the start. id say lift close to .550 with the 1.6 ratio. im new to picking out camshafts for performance. im a mechanic but mostly do stock repairs aside from simple cold air kits and such. im wanting to put this into a 70' duster ill be starting a thread on this weekend. bought it for $250 and it came with a v8 k-member manual steering four speed hump and linkage and best of all an a boby 8 3/4 rear for it! its going to terrorize local cheby and ferd dominated car shows. shell be far from original and comfortable but shell be fast and mean
 
I havent gotten them yet since their on back order and wont arive until the 30th i believe but ive heard some peope get lucky and they work just fine with stock heads and others say the wont clear the closed combustion chamber. Thats going to be the deciding factor on head selection between the magnum and the LA heads. Im hoping since the deck is uncut theyll clear pretty well
 
I'd stick with the "LA" head. A letter head would be best, IIRC. Port them out full on full tilt.
 
dustinmoran91 said:
thanks guys! im very appreciative for all of your answers. im wanting to stick with a production head to save money for the time being. i was considering the magnums because of the 1.6 rockers and the better flow than an LA head straight from the start. id say lift close to .550 with the 1.6 ratio. im new to picking out camshafts for performance. im a mechanic but mostly do stock repairs aside from simple cold air kits and such. im wanting to put this into a 70' duster ill be starting a thread on this weekend. bought it for $250 and it came with a v8 k-member manual steering four speed hump and linkage and best of all an a boby 8 3/4 rear for it! its going to terrorize local cheby and ferd dominated car shows. shell be far from original and comfortable but shell be fast and mean
Click to expand...


550 lift on a magnum head will need the guides shortened and probably valve spring pockets cut...
 
LA heads are sounding more like the way to go then. this is why i love this site! so many helpful answers and tips and tricks
 
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