Muzzyzx7rr

Hi from utah, I’ve got a 1970 c3 and just inherited a 1976 454 with 215hp I believe😰. Im wondering if you guys can let me know what kind of horsepower I’m going to get with this build. The block is in good shape with low miles and being bored .030 over
bore and hone
rebuild cylinder heads
grind crankshaft
resize connecting rods
and balance....

engine has stock 781 heads which I’ve read are great heads and I will add the following to the build at assembly

1)comp cams CB 270H-R10
2)edelbrock rpm Airgap
3)Holley ultra double pumper 850cfm 4bl
4)icon forged -38cc domed pistons

from what I’ve entered in the compression calculated this will bring compression to 10.86:1. I believe stock I’m at 7.8:1-8:1.
does anyone see issues with this build? I’m not sure if I didn’t go to much cfm on the carb. My end goal is to make this engine have the power that these made new with 70 454.
thanks guys!

NeverTooOld

Unless you're planning on racing it at a very high rpm on a regular basis I recommend using a dual plane intake and a #3310 vacuum secondary Holley. The operating range of single plane intakes is from 3000 to 7000+ rpm whereas the operating range for dual plane intakes is from idle to 6500 rpm. And a 454" running at an 85% volumetric efficiency can only consume around 670 cfm at 6000 rpm which is why a #3310 750 cfm is all you need..

Milan454

With the technology available today are you sure you want to limit yourself to 1970s power levels? Honestly I would go with more cam and a bit more compression. maybe a 294ish comp cam if you can swap in a converter. It will turn your car from a fun ride to an animal.

Muzzyzx7rr

To answer the first response. I’ve been having a hard time finding an intake that will fit under l-88 hood and I’ve searched online and everyone says Torker 2 is the only option. My preference would be performance rpm Airgap dualplane. Also yes I would love a bigger cam but don’t want to change torque converter for drivability I guess. I’m always open to input and yes I want a beast. It what do you think I’d make horsepower wise with the setup I listed?

ddawson

Torker 2 fits under the normal Big Block C3 hood. A L88 hood should fit an Airgap.

Muzzyzx7rr

What carb is the 3310 Holley? And nice to know about the airgap as that is my intake of choice. If I go with a bigger cam with a higher stall will the car still be streetable?

Muzzyzx7rr

Never mind I found the carb👍

Muzzyzx7rr

Thanks guys I changed my list to a 750cfm Holley double pumper and rpm Airgap. I should of done a forum search as I googled it and the question had been answered here before. Sorry about that. Is a 295 cam the duration of lift?? I’m kinda new to this and cams seem to be the complicated part so I’m still figuring that part out.

427Hotrod

The power is in the heads. That's where you want to spend the time and money. Those are decent heads to work with if someone who knows what they are doing does some port work on them. You're doing good on the forged pistons....if crank is in decent shape I wouldn't regrind it unless necessary. just a quick polish job. I assume it's a cast crank which will be fine if you don't get crazy.

A nice hyd roller cam will really wake it up if the $$$ are available. It will bring you better manners AND power with reliability. Make sure you get springs to match your cam.

The Air Gap is an excellent intake for this.

If for whatever reason you end up having to spend $$$ on crank and rods....I'd look into a basic 496 stroker kit. By the time you add up all the other work with turning a crank, resizing the rods, adding better rod bolts etc etc.....you can get close to really adding some power.

JIM

Muzzyzx7rr

Do you think I’m in the 400s as far as hp with my build so far? I don’t think I’m going to stroke it although a 496 sounds nice👍. I think a solid roller although I don’t know what one. I tried matching the 70 ls6 cam as close as I could which may have been a mistake.

Muzzyzx7rr

thanks jim you sound very knowledgable. And yes I agree if I have to spend money on crank and rods I might as well get the Stroker kit

427Hotrod

I wouldn't stay married to an LS-6 specs. It ran Ok but was nothing special...very mild.

You can get well over 500 easy enough with what you have.....do a search on VortecPro and look at some of his engine packages for an idea of what's possible. A lot of folks here have his engines and are happy. I've been to his shop and seen what he does. Very meticulous.

http://vortecpro454.com/

JIM

The13Bats

When i swapped my 383 for a mild 454 i didnt question much until it was done,
I was just thrilled to be back in a bb,

I did run the numbers,
My block is a 70s truck smogger block that should have had peanut port heads, but someone swapped to a better gm head, hum, ut was a fresh rebuild, with slight bloop to the cam

I have zero clue compression or cam specs,

The torkker 2 he had on it for stock hood really killed low end torque even on a bb,
Just the plain base performer woke it up big time,

Then several years ago i read a budget 454 build in a car rag like car craft,

Much to my dismay even using peanut port heads they were over 400hp,

It would seem bbs love to make power,
500 out of one is actually pretty common,

People love to over cam, build it in an honest way to how you will use it and run the correct compression and cam for what you want,

Muzzyzx7rr

[QUOTE=427Hotrod;1596109330]I wouldn't stay married to an LS-6 specs. It ran Ok but was nothing special...very mild.

You can get well over 500 easy enough with what you have.....do a search on VortecPro and look at some of his engine packages for an idea of what's possible. A lot of folks here have his engines and are happy. I've been to his shop and seen what he does. Very meticulous.

http://vortecpro454.com/

He has some really nice builds👍

it looks like I’m on track with my components, this build is more of a thing I’ve wanted to do with my dad for a long time so I’d like to do my owm😊. From everyone’s feedback it looks like a cam change is what’s really needed along with some port work on the heads I’m hoping to take this 454 to the 500 range!

jersey68l36

Almost 11:1 static compression with iron heads, what is you plan for fuel? If you plan on using pump fuel, you may want to work on valve timing, (cam selection) to kill off some compression. Do a Google search for Maverick Racing Compression Ratio Calculator to find out where you are. It been awhile, but for pump fuel, iron head, the target is around 9.5. roller cam, of course.

Muzzyzx7rr

thank 13 bats that is some good insight!

derekderek

Why iron 781 heads? Non-hardened seats, worn out guides. Port work is time-consuming so more expensive. You will have 1k in those heads and they won't be able to come close to AFR or Brodix alum heads. Eddy are little better flowing than iron rectangle heads. Unless you are set on stock for car shows or something i cant see them. And I think you are going with too much compression. 9:1 iron or 10:1 alum is pump-gas doable, even 87 octane.

Muzzyzx7rr

Ya I think I’m going to lower compression to 10.1:1 or somewhere around there and go with a mild enough cam that I don’t need to change stall. I’ll have rpm Airgap and hooker side headers and pipes so I think I’ll make plenty of power to have a beast😊 any other recommendations?

zmanabba

One of the things that hasn't been mentioned is to have the heads cut for bigger valves. Get 2.19 intake and 1.88 exhaust installed for better flow. It's a fairly low cost way to wake the engine up. If you already have the heads installed then you should have no problem reaching your goals with the proper cam. Just something else for you to ponder. LOL

Muzzyzx7rr

Seems like all I’ve been doing is pondering🤯