Abdullah

iTrader: (2)

i want to install BBC heads on a streetable chevy 502ci or 540ci big block in a 70-72 454ci BBC stingray corvette. i want to know what is the best heads out there.

i liked the AFR 325cc BBC heads.

what BBC heads are the best specialy for the street?

i want to just touch up the BBC heads by a good porter to get an efficient intake/exhaust ports i don't want huge ports just as small as possible and efficient with high port velocity and good flow numbers (not necessarily high flow numbers)

what kind of hp/tq i would get from the engine above 502ci to 540ci BBC with adequate cam and 11 to 11.5:1 compression and all other supporting mods?

i don't know about BBC's, all i know about are the LT1's which are basicaly a SBC's and LSX engines.

thanks for help.

Abdullah

iTrader: (2)

any one can help?

xx_ED_xx

iTrader: (17)

I would go with dart 310's

ulakovic22

iTrader: (12)

Any of the common BBC heads will work. Dart, AFR, RHS, Edelbrock, etc. I would stay around a 300cc intake runner, and nothing bigger than a 320cc, esp since you are going to have them ported.

Abdullah

iTrader: (2)

i'm between the AFR 305cc BBC heads and the AFR 325cc BBC heads.

the 305cc BBC heads have 2.25"/1.88" valves and the 325cc BBC heads have 2.30"/1.88" valves. both are as cast heads and no CNC is done to them except for the chambers. now if i choose any pair of these heads i will touch them up by a good porter, which set do you think that will give the best of both worlds torque and horse power?

thanks.

ulakovic22

iTrader: (12)

A question like that needs more information. Obviously a larger head is going to flow more, but where and how much depends on the cam which of course is based on the intended use of the engine.

Abdullah

iTrader: (2)

i want around 700 to 750 flywheel horsepower. do i need to do that with a big cam or a mild cam can be sufficient? i can go as big as 555ci BBC and 11 to 11.5:1 compression. i will install adequate size headers Borla exhaust system and i think i will go with electronic fuel injection i mean no carb. shall i go with a single plane intake manifold converted to EFI? or some intake manifold and throttle body closer in shape to the LT1 SBC intake manifold?

is there a good radiator and good fans that can cool this BBC?

ulakovic22

iTrader: (12)

You can get that number with a good sized hyd. roller. Would be easier to get an Edelbrock intake already set up for EFI and slap a 4 hole on it. What car is it going into? If you have the hood clearance you can run anything you want. If you are using a 4th gen then you need an elbow. I haven't run mine yet so I can't comment on radiator size, but you will need a bigger than stock. Lots of people run stock setups and have overheating problems when they start to drive them.

Abdullah

iTrader: (2)

i want to install the engine in a 70-72 stingray corvette. i think when i buy the car i will use cowl induction hood (not the factory shape), i will have a good hood clearance then for BBC, correct?. i want to use this car mainly for the street.

what heads are better for my needs and i should go with? a touched up AFR 305cc BBC heads OR a touched up AFR 325cc BBC heads for 555ci BBC?

thanks for help.

ulakovic22

iTrader: (12)

AFR 325 should work well on the street.

ZONES89RS

iTrader: (25)

Since it seams you have so much money to throw around with the bigger cube engines, go with a 565 short deck, the AFR 325s with the mild port work, a good Dart intake and a custom ground cam from Comp ot owards. You can tell them your compression, vehicle weight and flow numbers of the heads and intent of use and they will give you a great grind.

Abdullah

iTrader: (2)

thanks for the replies. actualy that heads i wanted to go with are the AFR 325cc BBC heads. i thought at first the AFR 325cc BBC heads could be some what too much for the street and thought the AFR 305cc BBC heads are more suitable for the street. my compression will be around 11 to 11.5:1, i think i will find a good radiator, fans and water pump to cool the engine.

btw, what are the specs bore and stroke of the 565ci BBC?

i wanted to go from the begining with a standard deck BBC.

J-Rod

The biggest standard deck engine you can build "reasonably" is a 582 or a 598. A 555 is a very common combo for this sort of setup.

http://www.ultrastreet.net/engines/582_bigdawg.asp
http://www.ultrastreet.net/engines/598_lowdeck.asp

I'd honestly point you at a Shafiroff engine package. Thjey have them on the shelf, they come with a warranty, etc...

As for the heads, on a bigger motor I'd probably look at the 325 ported as cast head. I probably would not touch them. But, if you know what engine you want to build, then I would talk to Tony Mamo @ AFR. Tony first program at AFR before the LS1 heads was to revamp their BBC product line. So, Tony can point you at which head would be best. Most of the AFR heads do not need additional port work, as they are optimized pretty heavily for a certain cross section area/port volume.

ZONES89RS

iTrader: (25)

565 is 3.6 bore and 4.25 stroke i believe. A 540 is common at 4.5 bore.

Abdullah

iTrader: (2)

you mean 4.6 bore for the 565ci BBC, (smile).

btw, can i bore the stock GM 502ci big block to 4.600" safely? what is the maximum bore for this block?

ZONES89RS

iTrader: (25)

I meant 4.6, typo. No, the safe for a 502 is usually 4.5, the world,merlin blocks and Dart big Ms usually are the ones that go 4.6

xx_ED_xx

iTrader: (17)

IF you are going to build that size motor a big m is the way to go

Abdullah

iTrader: (2)

OK, i have aquestion :

isn't a 4.500" stroke too much for the street and the pistons rings aren't going to live long or if i use a proper length connecting rods the short block will live long time of street use?

i thought 4.25" stroke is the max stroke if you want the short block to live long time on the street of street use.

ZONES89RS

iTrader: (25)

To use a 4.5 stroke, you generally have to go with a tall deck.

Tony Mamo @ AFR

iTrader: (13)

4.375 is max recommended for a low deck block....

Figure out what your going to build and touch bases with me after you do.

A 325 with a CNC chamber upgrade or a full port 315 or 335 will likely work the best depending on what final displacement you arrive at.

Our heads took top honors in a seven manufacture playing field that was done by Chevy High Performance about 12 months ago....it was an exhaustive test with every head flowed and every head cc'ed to verify they had the same chamber volume to keep the compression ratio on an even playing field.

The AFR BBC line up is a really effective product (as is most things we produce cylinder head related!).....contact me when your closer so I can help guide you into the right one but the three I mentioned are probably what we will ultimately choose from based on other factors surrounding the build.

Cheers,
Tony