ok so my hsr set up came in from summit today woohooooo, also got my heads dropped off at my local machine shop so far the heads have been cleaned up an checked for cracks an they passed with no cracks or warping. i plan on using the stock springs, rockers, etc the only thing i plan on doing is opening up the intake ports to 2.02 an also opening the exhaust ports to 1.60. my main concern is what cam would be good to use for a hp rating of 330hp an 335 ft.lbs tq at the fly while staying in the stock lift of the vortec.s which i believe is .470-.490 i found this cam an seems like it will work just fine.

http://www.summitracing.com/parts/cca-12-402-4

for injectors im using venom 24 lbs, an for throttle body i got a lt-1 58mm from summit racing with throttle lever adaptors to use the lt-1 style cable or the stock tpi cable which is a good thing doesnt include iac valve or tps but i should be able to transfer over my tpi stuff to it

 

I would read through this. Please let us know if you have the same issues:

https://www.thirdgen.org/forums/memb...lth-ram-1.html

 

yea thanks for that link ill keep this saved for future reference when i start to disassemble the 355. but back to topic i need to know if this cam will help out to meet my estimated power rating in hp an tq i was also wondering if the lt-4 cam will work with non roller style blocks an what i would have to get in order to make it work

 

I would just try to keep the lift under .520 and use beehive springs. An XR276 is known to get 350-375hp. The LT4 Hotcam is good for 325-340ish. The problem with an LT4 hotcam is it requires a factory roller block timing chain, so no room for a cam button. There's a product out there that provides a spacer behind the cam gear that allows you to install it, but I dont know what you would do about endplay. Then you just use linkbar roller lifters and get new pushrods and you can run a factory roller cam in a non roller block. The main difference is just on the cam snout, as the factory cams had a thrust bearing/retainer setup in the front that forced a smaller bolt pattern for the cam gear.





This is a retrofit-roller cam, it has the same type of cam snout as a flat tappet cam.


Thats the only difference as far as Im aware. Note that retro-roller cams use the same timing chains as a flat tappet motor will.

These are the type of lifters you need:



Also the flat tappet cam you listed is probably only good for 260-275 crank horsepower.

 

http://www.lingenfelter.com/mm5/merc...egory_Code=C30

 

Yeah you keep posting up that thing and I keep forgetting to bookmark it! Done!

 

ok so maybe i can get some help with a cam decision that will put me in the 330 crank hp i wanna keep a hydraulic flat tappet cause i plan on transferring everything from my 70's 194 crap heads over to the vortec heads comes out cheaper instead of buying new pushrods an everything else they have less then 2000 miles on them anyway so pretty much need a cam an lifter combo an i should be good mostly wanna go with a comp or a lunati cam if that matters. also where can i get this XR276 cam from an what brand is it ???? is it a hydraulic flat tappet or a roller style cam also will it work with the efi setup

 

If you're gonna re-use springs you dont need to go any bigger than stock.

XR276 - http://www.summitracing.com/parts/cca-08-423-8

An xe274 will probably get you near the 325-350 range.

Xe274- http://www.summitracing.com/parts/cca-12-246-3

The xe274 wont be nearly as streetable. you're gonna need nice valve springs, 3.42-3.73 gears, and mid 9's in compression at least. An xe268 is a much better choice, but is gonna leave you in the 310-325 range.

This article right here is VERY informative:

http://www.hotrod.com/techarticles/h...s/viewall.html

Just remember the dyno numbers are an engine with a perfectly tuned carb on a good intake manifold with huge long tube headers etc etc and it doesnt even have to turn its own accessories (no water pump, power steering, alternator, etc). The real crankshaft horsepower numbers will be lower when installed on your car, but it will tell you a lot about how different cams compare to each other. Use it as a reference to gauge one cam vs another, not to get a real world number.

The xe268 makes 365hp on their dyno, my real world estimate is more like 315.

 

the xe268 cam will work perfectly im placing the order to summit now for it im also getting the lifters to go with it also instead of ordering the venom injectors i was wondering if lt-1 injectors will work as long as they are 24lbs i believe they were after 1993 model lt-1's. can someone clarify that with me i found a whole set of lt1 injectors new from rockauto.com for only 140.00 dollars really good price if you tell me an shipping is cheap as well.