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-   -   stock bbc 454 vortec (http://www.hotrodders.com/forum/stock-bbc-454-vortec-182365.html)

dre1984 08-07-2010 07:56 PM

stock bbc 454 vortec
 
i have a stock 454 vortec and was wondering what can i do to add more power with a good sound. i have a few parts laying around such as a 850 carb, dart single plan intake, hooker super comp headers and nitrous i dont know if the vortec bbc head is a good head to use if not i have a set of 390 ported and some 049 i need help chooseing a good cam and which of these parts i should

cobalt327 08-07-2010 11:13 PM

Quote:

Originally Posted by dre1984
i have a stock 454 vortec and was wondering what can i do to add more power with a good sound. i have a few parts laying around such as a 850 carb, dart single plan intake, hooker super comp headers and nitrous i dont know if the vortec bbc head is a good head to use if not i have a set of 390 ported and some 049 i need help chooseing a good cam and which of these parts i should

Gen 5 or 6?

dre1984 08-08-2010 07:40 AM

its a gen 6

cobalt327 08-08-2010 08:19 AM

The stock Vortec 7400 heads are net lash- to do much w/them the first thing that would be needed is to swap out the studs and lock nuts for adjustable ones.

Both Vortec 7400 heads (the '98-'01 12560241 and the '96-'01 10141279) are about 100cc, as a comparison. As you can see HERE, much care has to be used if porting these heads, they have a "peanut port" sized intake port w/a vane cast into the port as well.

The 049's (113cc-plus chambers) would flow well, except the Gen 6 has basically a FT piston, and that will kill the CR w/the open chamber heads. The 390's have smaller chambers (about the same as the L-29 heads) and so would be about the best compromise, IMO.

dre1984 08-08-2010 09:37 AM

ok i would be using the 390 casting do u think my dart single plan intake will be to much also will like to use 125 to 150 shot of nitrous

GMC boogie 08-08-2010 03:59 PM

Can Mark 4 heads be used on a Gen 6 block? I have heard otherwise..something to do with the coolant passages.

dre1984 08-08-2010 06:53 PM

yes gen 4 heads can be used on gen 6 but gen 4 heads cannot be used on gen 5

DoubleVision 08-08-2010 08:05 PM

You want to run the open plane intake then what are the rest of the mods? What rear gears? what transmission? If just adding heads and a moderate cam to it I would use a dual plane intake and plop the 850 carb on it. I don`t know the power band of the dart intake, but if it`s the 3000 rpm and up design then you`ll need to tailor the rear gear and cam to it`s power band.

nova327 08-08-2010 08:22 PM

I think the headers would help and the single inplane may be a little to rpm range than you want. Your cam choice will come from where you want you powerband to be? ? comp cams have nice packages for the money. put a set of roller rockers also. You may have to do some work to these heads for rockers? i am unfamilar with them

cobalt327 08-08-2010 11:40 PM

Quote:

Originally Posted by dre1984
yes gen 4 heads can be used on gen 6 but gen 4 heads cannot be used on gen 5

First, it's MARK IV (or 4) not gen 4, and there are gaskets made specifically for using Mk. IV heads on a Gen 5 block. These are what you want (from a V/R press release, presumably prior to the Gen 6 engine release):

General Motors 7.4L Head Gasket
Issue:

General Motors (GM) 7.4L (454 CID) engines use two types of engine blocks: the Mark IV and Mark V. The Mark IV is found on 7.4L engines in model years from 1965 to 1990, and the Mark V is found on 7.4L engines in model years from 1991 and newer.

Often, installers will attempt to adapt a Mark IV cylinder head for a Mark V block. This conversion can be made if attention is paid to the coolant circulation. Mark IV and Mark V have different coolant flows and were originally designed for different head gaskets. If the conversion is not performed correctly, the engine will overheat, causing premature engine wear and damage.

Resolution:
Victor Reinz has designed two Nitroseal® head gaskets to specifically allow for this conversion. The installation requires Victor Reinz part number 4918 be installed on the right cylinder bank to maintain proper coolant circulation, and part number 4923 to be installed on the left cylinder bank for the correct coolant flow.

Application:
Victor Reinz part numbers 4918 (right bank) and 4923 (left bank) are available for GM 7.4L (454 CID) engines.

dre1984 08-09-2010 03:40 PM

the dart intake starts at 3500 to 8500 my compression is at 9 with a 350 trans gear i want to run is either 373 or 410 what i need help with is picking out a cam that would work with a 9 to 1 compression along with the dart intake dont have a converter yet but looking towards one that will work with the intake and cam

cobalt327 08-09-2010 05:17 PM

ok so what you might consider doing is to dump the intake that you have and invest in an rpm intake instead of the ill suited open plenum intake ill suited at least for the street unless you can figure a way to get more cr to use a bigger cam w/a power band that better matches the intake the problem i see is with a mismatched combo we see it all the time guys want to use an intake made for a 240º cam and 10.5:1-plus cr on a 9:1 engine at least you have enough carb

dre1984 08-09-2010 08:52 PM

the intake was intended for my 496 that i have aside and was hoping i could have came up with some kind of combo that would make the single plan intake work on the 9 to 1 454 so the dual plan is the best way to go

cobalt327 08-09-2010 09:01 PM

thats my opinion but like they say opinions are like butt holes everyone has one lol the dual plane intake will get you more bottom end with 9:1 cr you cant run too much cam or the whole deal will start to reek you could easily trade that single plane for a rpm or other good dual plane or just bite the bullet and get another intake


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