Double hump heads

[blazin_blazer]

possibly you are rite

but ive seen bbc headers made to fit sbc..they may have tweaked the tubes but they were 100% homemade by the son of a man who owns a muffler shop. he made them for a derby car and even built his own flange...and i still stand by the fact that 2 of my friends have bbc headers on their boats with an adaptor made by the same guy above, maybe they heated the tubes cherry and tweaked them but they are bbc headers they run over the transome with the water cooled headers...now that you mention it i do remember them talking about having to grind an angle on the flange toward the middle and the tubes were like close to half offset on both ends....i've only talked to my miracle machinist twice and the second time is when he said "you know your going to need to run something like bbc headers on this thing ," he then stated they had an adaptor to do this and i guess i assumed he meant an adaptor to put the bbc headers on the sbc....he maybe talking bout adators like i linked to, but that does not change the fact i've seen several people make bbc headers fit their sbc....so learn me sum'n what is stahl headers...brand name?they dont sound like big tube adaptors they only have an 1 1/8" square port i guess you match these to your heads then dump into big tubes?

 

[beater_k20]

Stahl headers are a modified small block Chevy flange, which moves the bolts around specifically to clear larger tubes.

got any pics of these "big block" headers on a small block? more than likely, probably not.

BTW, the headers you described are also available to fit a small block Chevy.

 

[Leadfoot]

I think what Beater is trying to tell you is that if you look at an SBC head the two middle ports are right next to each other (Drivers side front to back: exhaust port/pipe cylinder 1, space, exhaust port/pipe cylinder 3, exhaust port/pipe cylinder 5, space, exhaust port/pipe cylinder 7)
O OO O

whereas a BBC has evenly spaces exhaust ports (Drivers side front to back: exhaust port/pipe cylinder 1, space, exhaust port/pipe cylinder 3, space, exhaust port/pipe cylinder 5, space, exhaust port/pipe cylinder 7)

O O O O

A BBC header CAN be bastardized to "fit" and it's not terribly hard for someone with the correct tools/knowledge. This would be great on an SBC engine that is turning 9000 rpms consisistantly and needed the flow, but it would also be an engine that has been heavily modified and using a sheetmetal intake and HEAVILY machined (SEVERE porting) heads to even begin to see the benefits of that large of a tube header.

You can put whatever you want on your rig (free world), but on an engine that is street driven and off-roaded, or even just offroaded (i.e. varying rpms) than the money would be poorly spent and most likely DECREASE performance which I don't think is your intention (which I missed if you stated it).

If you are planning to build a truck for the Bonneville Salt Flats ONLY than you might be on the right track, but if you plan to drive this on the streets (at all) than I think you are going to run into problems with the setup you describe.

Also as you state a predator works off of engine demand so it shouldn't "overcarb", but they are not known for great idle or streetability/off-roadability. Yes there are guys that run them and they can work, but most run them solely for "cool factor" and not broad range performance (mostly conserned with sustained high rpm's).

Again it's a free world and you can do what you want, and I'm not trying to bash you, just thought I would lend you some free advice as I have learned the hard way over the years.

 

[blazin_blazer]

the truck this engine is destined for

probally will not see much if any mud at all ,,,i just cant think ove sinking a $10,000 motor it will be a beach cruiser and a mall brawler...my machinist told me to get the most out this 427 sbc i would need some larger tube headers ....i told him the motor is cammed to 6-6500 rpm, he told me i would still need bigger headers....so i have my cam grind # and he told me to call lunati back and ask what size tubes was they using in the desktop dyno or whatever program they use, so that is next on my agenda.....about the bbc headers on sbc ..they were rigged that way because it was what they had, it went into derby car amd has been scrapped for 3-4 yrs now...i will see if i can catch up with my cousin over thanksging...because i upped and moved about 3 hrs from all my family up to the super nice and clear lake of greers fairy and away from the muddy water's of helena...but i go back quite abit trailering an '80 blazer, but i will try and check with my cousin,he's the 1 with the bbc headers on a sbc designed to turn 8-10k because on a boat once you get out of the hole its all bout how fast can you spin that impellar he had to make a scoop on the bottom of his boat to keep the pump from cavitating

 

[beater_k20]

...about the bbc headers on sbc ..they were rigged that way because it was what they had, it went into derby car amd has been scrapped for 3-4 yrs now...i will see if i can catch up with my cousin over thanksging...because i upped and moved about 3 hrs from all my family up to the super nice and clear lake of greers fairy and away from the muddy water's of helena...but i go back quite abit trailering an '80 blazer, but i will try and check with my cousin,he's the 1 with the bbc headers on a sbc designed to turn 8-10k because on a boat once you get out of the hole its all bout how fast can you spin that impellar he had to make a scoop on the bottom of his boat to keep the pump from cavitating

is there a sewage leak in the garage?

 

[blazin_blazer]

huh?

huh?

 

[beater_k20]

i smell bull****. look at the underlined text in my reply, kinda contradicted yourself there didnt ya?

 

[blazin_blazer]

not that i know of

how i said the 1's i had seen where on boats and derby car????????

 

[beater_k20]