new cam???

[grumpyvette]

Hey guys so i have a 84 with crossfire removed. I have had the 350 bored .30 over with flat top valve relief pistons. I have procomp heads 190 cc runner and 64 cc chamber. I've had some work done on them to clean them up. 2.02 intake 1.60 exhaust. It has a comp xe 262 cam and edelbrock performer rpm intake. Holley 770 street avenger. Car runs strong but what power is it actually making. The machine shop who built the heads also builds supercharged cars. They actually build superchargers mostly but he knows engines too. He said i should be right around 425-450 with this set up. Is he about right? He said i would benefit from a slightly larger cam what do you guys think? I want to run low 11. My next investment is a dana 44 upgrade or at least gears.

http://www.corvsport.com/Corvette/C4/1984/C484_Spec.html

your original 1984 engine produced 205 horse power and 290 ft lbs of torque

AS in almost all engine builds the key to building a good combo,is well matched components ,desk top dyno softwares predicting this, result running the stock exhaust system with your current listed mods, which would result in about 100 plus rear wheel hp, and 100 ft lbs plus more that the original engine,ID be very VERY surprised if your engine built as you listed exceeded 400hp, which is still a HUGE improvement over the original configuration, as its nearly double the original power level

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ID expect the car to run low to mid 13 seconds currently why not take it to the local track and see?

yes 3.73:1 gears and a slightly larger cam will help.
what transmission are you running, if its an automatic youll want a 3200 rpm stall converter to run the type of cam required to take full advantage of the new rear gear and a longer duration cam

just for giggles I tried several cam up=grades in the desk top dyno software along with a 3200 rpm stall converter and a 3.73;1 rear gear

heres one of the better predicted results, at near 430hp/430tq with the drive train upgrades and new cam, of course thats only what software predicts it could easily be a bit more or less depending on how your engines assembled and tuned, and cams larger than that tended to loose low rpm torque faster than the gains in upper rpm power

Now if you have a manual transmission , and ideally a low restriction exhaust (2.5" min, 3" ideally) with an (X) pipe and headers like you should have to maximize exhaust flow
the better flow rate exhaust should increase all the dyno numbers by about 15-20 hp over whats posted, if you have low restriction mufflers , but , if your thinking of upgrading that flat tappet hydraulic cam, Id seriously consider selecting a cam that has a fairly tight 108 lsa and about 228-230 duration,and near .480-.510 lift as thats what all my dyno software programs suggests matches the best, in a flat tappet hydraulic.
now if you have the cash to spend a hydraulic roller cam might be a better option, then a cam like this, matched to the 3.73 rear gears, but obviously a roller cam will require better valve springs and accurately checking clearances, and 1.6:1 roller rockers certainly would not hurt at that point

this is what the DD SOFTWARE MAKES ITS WILD GUESS AT WITH THE ROLLER CAM AND ROLLER ROCKERS

the most common upgrade ive found that works very dependably on the TPI and MANUAL TRANSMISSION cross fire cars is
the crane powermax 2040 cam , upgrade,it is a great lower cost upgrade to a otherwise nearly stock TPI, or a manual transmission cross fire ,and about as large as you can go with an increase before it starts requiring mandatory other changes, even with the crappy stock heads its worth 25 hp in the crossfire and 35 in the tpi and it works with all the stock components without problems.
yes it works best with 3.54:1 -3.73:1 rear gears and an adjustable fuel pressure regulator , and 1.6:1 roller rockers,and long tube headers, but it FUNCTIONS and provides a noticeable boost,even without those components