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Discussion Starter #1
i have a 91 s10 4.3 i would like to cam my truck and put aftermarket roller rockers which would give me the best performance gain with out haveing to mod mold or grind nething and have clearance. my dad works at edelbrock and was gonna get the cam from them
#3714

ENGINE: CHEVY 4.3L 90° V6
RPM RANGE: 1500-5500

Duration at 0.006" Lift:Intake: 272°Exhaust: 276°Duration at 0.050" Lift:Intake: 210°Exhaust: 214°Lift at Cam:Intake: 0.319"Exhaust: 0.325"Lift at Valve:Intake: 0.479"Exhaust: 0.488"Timing at 0.050" lift:OpenCloseIntake:2° ATDC32° ABDCExhaust:44° BBDC10° BTDCCenterlines:Lobe Separation - 112°Intake Centerline - 107°
 

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you might want to find something with a lobe separation angle of 114. if your going with that duration. you dont have too. but it might make it easier to tune if your keeping fuel injection. also as far as grinding heads, i am unsure if the guides are to tall on the older heads or not. but no problem all you have to do is run a set of comp cams beehive springs (the 26915's are about perfect for that size cam imho, just be sure to get the correct locks and retainers and your good for .55 lift even on newer vortec heads) and you shouldn't have any problem with lift as long as you use the right ratio rocker arms (ie. 1.5 ratio if the cam says ".479 lift with 1.5 rockers", with that cam i bet some 1.6 ratio rockers might work, kind of pushing it near the limit on the exhaust but.... you can always check for clearence, and even if you have to machine the heads its not too hard and the tools to do it are realitivly cheap), i do suggest (if in budget) newer vortec heads and eldebrock 2114 mainifold if your tbi and still staying with tbi (or carb), since they will give a good power increase. but besides that and a good exhaust, its all in the tune, either carb or fuel injection. good luck
 

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IIRC, the 91 is already a roller engine. The Edelbrock cam was meant to be a drop in replacement as is their TBI manifold. You may also want to look at a replacement Holley TBI unit as the extra size will allow more airflow. (and if newer style heads will fit and are designed differently then those would also be a great imporvement.
 

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Discussion Starter #4
IIRC, the 91 is already a roller engine. The Edelbrock cam was meant to be a drop in replacement as is their TBI manifold. You may also want to look at a replacement Holley TBI unit as the extra size will allow more airflow. (and if newer style heads will fit and are designed differently then those would also be a great imporvement.
well my mechanic is gonna do the work hella of a good one and i already have the holley tbi only thing missing is the cam so edelbrock is fine with maybe pro magnum rockers 1.6
 

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I would look for a cam with more duration like the Comp Cams 270 AHR. It has 215 intake/220 exhaust duration. Maybe Edelbrock has something similar.

As long as you use the Comp Cams or Chevy "Beehive" valve springs with Comp Cams #787 steel retainers, you shouldn't have to worry about extra machining on the heads.

Click here for info on aftermarket roller rocker arms. The stock roller trunnion rocker arms used in 2000+ 4.3s are good too.
 

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Discussion Starter #6
I would look for a cam with more duration like the Comp Cams 270 AHR. It has 215 intake/220 exhaust duration. Maybe Edelbrock has something similar.

As long as you use the Comp Cams or Chevy "Beehive" valve springs with Comp Cams #787 steel retainers, you shouldn't have to worry about extra machining on the heads.

Click here for info on aftermarket roller rocker arms. The stock roller trunnion rocker arms used in 2000+ 4.3s are good too.
im only doing the cam from edelbrock simply because its not gonna be as expensive wold the these...
Crane Cams 10759-12, 1.6 ratio Gold Race
work fine and help the cam produce more?
 

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im only doing the cam from edelbrock simply because its not gonna be as expensive wold the these...
Crane Cams 10759-12, 1.6 ratio Gold Race
work fine and help the cam produce more?
Yes they would. But it would probably be cheaper just to buy a cam with more lift. Did you read the article I linked you to above? It's a lot of work to install roller rockers on a '91 head:
"On this type of engine you have basically one option. Remove the studs, drill and tap the head to accept a 7/16" rocker stud, install a 7/16" bottom X 3/8" top stud and use a set of narrow body rocker arms. This procedure should only be done with the heads off the block which makes it one of the most difficult procedures."
Plus, you have to buy a set of studs, in addition to the rocker arms.
 

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Discussion Starter #8
Yes they would. But it would probably be cheaper just to buy a cam with more lift. Did you read the article I linked you to above? It's a lot of work to install roller rockers on a '91 head:
"On this type of engine you have basically one option. Remove the studs, drill and tap the head to accept a 7/16" rocker stud, install a 7/16" bottom X 3/8" top stud and use a set of narrow body rocker arms. This procedure should only be done with the heads off the block which makes it one of the most difficult procedures."
Plus, you have to buy a set of studs, in addition to the rocker arms.
should i just stick with the edel cam. or the 270ahr. and just leave it at that
 

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Discussion Starter #10 (Edited)
I would want the 1.6 rockers with the Edel. cam or the stock rockers with the Comp Cam.
so i should do the comp cam with what u said to do with the beehive springs and new retainers and rockers. ( with those i wouldnt have to machine)

im sorry i reread what u posted i think im gonna go with the 270ahr cam would be a better perfomance correct
 

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so i should do the comp cam with what u said to do with the beehive springs and new retainers and rockers. ( with those i wouldnt have to machine)

im sorry i reread what u posted i think im gonna go with the 270ahr cam would be a better perfomance correct
Yes. More power. The Edelbrock would have more low end torque but less power.
 

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The Edelbrock cam your Dad can get is just fine for a good boost in all around power, It's a drop in replacement, it requires no machining, and nothing special to install! Forget the 1.6 rockers, I see no reason to go any hotter on a cam,,, these specs are very similar to a 350 Chevy/350hp hi lift hydraulic, only in a V6 configuration, How much power do you want? or need?

Unless you want to have a lot of machine work done, spend a lot of money, lose some low end torque, with rpm you can't use at the top end, plus a lumpy idle for bragging rights :rolleyes:
 
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