Guest Anonymous Posted December 27, 2001 Share Posted December 27, 2001 I plan on putting a 350 into my early 260, but I want to build it up so that it redlines above 6 grand. It needs to be streetable and I'm on a budget. Thanx Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted December 27, 2001 Share Posted December 27, 2001 ok lets look at one of the better CHEAP COMBOS http://Parts@sallee-chevrolet.com/Cylinder_Heads/Vortec.html YOU MUST ADD BETTER SPRINGS AND CLEARANCE FOR .550 lift Applications Application Series & Grind Number Fair idle, moderate performance usage, w/plate or manifold nitrous system, good mid-range torque and HP, bracket racing, 3400-3800 cruise RPM, 10.0 to 11.5 compression ratio advised. Basic RPM 3000-6500 PowerMax F-278-2 replacing: CC-278-2 Cam Specifications/solid lifter flat tappet cam Degrees Duration @ .050 Int./Exh. Degrees Advertised Duration Int./Exh. Degree Lobe Separation Open/Close @.050" Cam Lift Int./Exh. Lash Hot Int./Exh. Gross Lift Int./Exh. 238/248 dur @ .050 114 lsa .480/.500 lift Super Victor for Vortec Heads #2913 700cfm carb, you will need a good high rear gear like a 3.5-4.1 to get this to run at its best and a manual trans or a higher than stock stall converter will help to but this should get you 420 hp and 425 ft lbs Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 28, 2001 Share Posted December 28, 2001 Thanx. I have a few questions though. What is the redline?. And how can i make it higher? Any help would be great. Quote Link to comment Share on other sites More sharing options...
Guest Will Posted December 29, 2001 Share Posted December 29, 2001 The bottom end of any 350 ever built will go to 6K or beyond. What you have to worry about is the valvetrain. With a rev-kit, appropriately stiff valvesprings, a generally well built valvetrain, and reasonably strong rods, you could wind it out to 7K all day long. Quote Link to comment Share on other sites More sharing options...
QWKDTSN Posted December 29, 2001 Share Posted December 29, 2001 How do forged pistons, aluminum 1.5 rollers, and Schneider valve springs (6700 rated) sound? I'm hoping to get at least 6500 reliable RPM out of my motor but I won't push it if I have any doubt. Quote Link to comment Share on other sites More sharing options...
Guest gbvol54 Posted December 30, 2001 Share Posted December 30, 2001 A question on upgrading the springs on Vortec heads: I just bought a set of stock Vortec heads. I realize the stock springs are limited to .450 lift and, as you stated, I'll need to upgrade the springs for more lift. Comp Cam lists what they call "a direct drop in" set (#981). Is this indeed all I need and if so what lift will these give me? Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted December 30, 2001 Share Posted December 30, 2001 there are several things that effect the max lift your heads/springs/retainers can handle other than (spring bind) look at the diagram here. http://www.cranecams.com/master/vsprings.htm .read this http://www.hotrodheaven.com/comments/messages/9058.html now with cheap springs its usually the spring coils stacking up and (binding) that limits the amount the valve can be opened but the bottom of the retainer hitting the top of the valve seals/valve guide comes in as a close second in the race to cause clearance problems so you must check that too! just adding the better springs that are normally rated at either .540, .575, .600 will give you more clearance but in most cases Ive measured the retainer /seal clearance will limit you to about .500-.510 if your just changeing the springs, if you want to do it correctly and don,t have the measureing equip. just take the heads down to your local high performance cylinder head rebuilder and have him machine the valve guides for the .600 lift clearance and have him use these valve seal,(Hi-Performance Teflon Seals) (Machining Required) read this http://www.cranecams.com/master/vmisc.htm and this http://www.babcox.com/editorial/ar/ar79842.htm Quote Link to comment Share on other sites More sharing options...
Guest gbvol54 Posted December 30, 2001 Share Posted December 30, 2001 Thanks Grumpy, Just the sort of info I needed. I'll go away and study for awhile. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 3, 2002 Share Posted January 3, 2002 so, just to keep this thread goin, what type of valvetrain do you guys recomend for a 6500+ RPM engine. Please keep in mind this is a street car. Thanx Quote Link to comment Share on other sites More sharing options...
Guest jwelch Posted January 3, 2002 Share Posted January 3, 2002 Hi GrumpyVette, I have a question too, on lift. The present cam I have is a comp cam 12-238-2 (218 in./224ex.@.050") the intake lift is .462 and the ex. is .469 Will this work on a stock set of vortec heads? I have a set of high performance springs on my current heads, I believe they are good to 8K RPM, could be wrong. I know the lift is well over .500 on these. If the vortec springs won't work can I just do a spring swap with the ones I have? Thanks Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 3, 2002 Share Posted January 3, 2002 yes jwelch that cam is a good choice for a street driven engine with vortec heads and no clearance problems are normally involved, and depending on other options of course will give about 340hp and 390 ft lbs makeing it one of the better heavy car cams,in fact its one of the hottest cams that seems to run without causeing trouble in most cars and one of the few that are almost a NO_BRAINER choice almost GUARANTEED to run well! Quote Link to comment Share on other sites More sharing options...
Guest gbvol54 Posted January 5, 2002 Share Posted January 5, 2002 With the Vortec heads, a cam of the type jwelch described, and 10 to 1 compression, is the Performer RPM a good choice for intake? What performance gain does upgrading to an Air Gap model provide? I detonation going to be a problem with this combo? Quote Link to comment Share on other sites More sharing options...
Guest gbvol54 Posted January 5, 2002 Share Posted January 5, 2002 Should read as "Is detonation going to be a problem. (I'm lost without a spell checker) Quote Link to comment Share on other sites More sharing options...
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