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#1
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Ram Air III vs Crower 60243 cam
Ok ive got a 1971 455,3.55 gears,4 speed/4bbl/ getting ready for a rebuild and my machine shop recommended a Ram Air III cam. Ive heard alot on this board about Crower 60243.
here are specs ive found: Int / exh / int@50 / exh@50 / lobe 284 / 290 / 228 / 235 / 112 crower 301 / 313 / 220 / 228 / 110 ram air III any comments on this? The ram air looks like a bigger cam to me but i dont know sap about cams. He said the Ram air 3 can retain stock rockers. |
#2
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i myself am a fan of the RAIII cam, but thats personal preference
makes a nice sound, broad power range, however for making max power there are better ones out there I have the lunatti version, which is choppy in the 400, not sure how it would be in a 455 the III cam is great for manual tranny's just make sure to pick the cam that matches everything else that you have for optimum performance also the III is very easy on the valvetrain too, even with 1.65 rockers |
#3
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Not sure wich cam you refer to as the RAIII cam?
Here is the original specs: Pontiac 9785744, 301 313 advertized, 224 236 @ .050", .410 .410 lift, 119 LSA, 76 overlap. I use it myself in my 455 with #96 heads RA exhaust TH400 and 3.55, runs 13.7 with tires spinning half the track (regular tires). This cam MUST have valvesprings with approximately 125lb @ 1.586" installed height due to the shape of lobes. Valve float WILL occur at lower rates. |
#4
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#5
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Some gearing would help too, Pontiac used 4.33 in the 1967 GTO RamAir as standard gears with the #744 cam.
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#6
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Quote:
It wouldn't need the 3.55's unless he just liked spinning the tires a lot...........
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frittering and wasting the hours in an off hand way.... 1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core. |
#7
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For a 455 3.55 is plenty, iīm leaning on a 3.07 for my Judge wich i think would be perfect for this combination? Didnīt the 455SD T/A use 3.07 gears for A/T? |
#8
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Probably wouldn't need too much converter with that 4spd........
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frittering and wasting the hours in an off hand way.... 1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core. |
#9
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Quote:
MTC, Stewart
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1976 TA, nose converted to 1970 style, 406, ported #13 Heads, '70 iron intake without crossovers, Q-Jet - Cliff style, RARE OS manifolds, Pypes duals w/crossflow, UD 230/238 custom HR 4/7 swap cam with solid roller lifters , Hydro-Boost 4-wheel discs, 4 Speed, 3.23 posi. Nothing in life is so exhilarating as to be shot at without result. - Winston Churchill |
#10
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1967 GTO HO/RA TH400 code is PX. |
#11
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#12
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RustyCarr i think you are looking at the Lunati Ram Air III cam 424 lift/ 220 228 duration.You shouldn't have any problems with that cam.I have ran a Ram Air IV in a 455 with 96 heads with a 3.23 gear and it was my everyday ride.What heads are you running on your 455?
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#13
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stock 1971 455 heads, i think they are #66
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#14
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Definitely use the 112 ls Crower on a 8:1 455 over a 115.5 ls #744 cam.
If you had 9:1 or more, then I would use the 744 ..
__________________
63 Catalina coupe 455 budget drag car 11's 1/4 , 7.4 1/8th 66 Star Chief Executive 57k mile 69 Le Mans 2 dr HT 350 85k mile 15 sec 1/4 69 Firebird 400 Burgandy/Black 70 Olds Rallye 350 F85 4 speed 3.91's 70 Olds Cutlass Cruiser Red Wagon 350 101k miles 15 sec 1/4 12 sec w 455 74 Cheyenne Super C10 LWB Gen 6 454 w ZZ502 cam 3.07gear 13.1 1/4, 8.3 1/8 2020 RAM 1500 SLT 4x4 5.7 A8 Hemi 2007 Hummer H3 3.7 liter turd 2019 Chevy Spark petrol car 38 mpg |
#15
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Hey gang; I have used the 744 with 3:55s and 3:90s. In both cases, it ran great, In one case I had it in a 66 tricarb 389 gto -the car was easy to drive. I was running a wide box, 3:55s, and 1.65 rockers and H.O. racing specialties ram air springs-it would routinely pull with power past 6 grand. I swaped it out for an nos 041 in the tube I found at Pomona in 91, car ran like gangbusters-unbeleveably strong to 6+. In the other car, my current ride, a 69 special order paint (code 72) GTO, I have the 744/413 cube combo driving a another wide box and 3:90s. Again, a strong streeable combo-you won't be top eliminator at a national meet, but you will be strong on the street. Another thought- the 068, 744 and 041- all designed for cars waranteed for the days of 5yrs/50,000miles-designed by pontiac engineers for pontiac engines-they worked well together-just my 02cents.
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#16
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Are the heads still press in studs or have they been changed to screw in studs.I used a Ram Air IV cam in a 73 [stock]4x headed 455 before and i ran 8.90's [1/8 mile] with a 3.23 gear.But with a press in studs i would go with the cam with the smaller lift.
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#17
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The larger 744 Ram Air III camshaft has never been overly popular. It was the last effort by the engineers to continue to add duration without increasing valve lift. I think they may have started down the path of diminshing returns with it, not sure?
What I do know is that when they werer still readily available, I tried one in a well prepared 428 engine. It ran fine, tad "rough" idle and decent power, but I wasn't overly impressed with this cam anyplace. The engine lost a thrust bearing early in it's life, and was rebuilt with an HO Racing HC01-A camshaft. The higher lift cam just worked better everyplace. Improved idle, stronger mid-range and pulled equally as well at high rpms as the 744 camshaft. At that time our car didn't hook well enough or run consistant enough for averaging track numbers. We also changed from #96 to 6X-4 heads during the overhaul/rebuild, so the numbers would be flawed anyhow. The new engine did propell the car considerably faster than the old one, and we liked it's street manners better at every level. The Crower 60243 cam is an excellent camshaft in the 400 engine with at least 10 to 1 compression, 3.73 or higher gearing, and manual transmission or at least 3000rpm stall converters with the auto trans. I haven't used or tested one in a 455, but have recieved excellent feedback from users of them in that application. Personally, if being used in a 455, I'd limit the SCR to about 9 to 1 or just a tad higher. Above that I'd move up to the 60919 grind......Cliff
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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