Building an 11 second 70's nostalgic SBC

[ClassicRob]

https://www.castheads.com/cylinder-head ... ump-heads/

Maybe these guys?




A suggestion to surpass your power and et goal while remaining period correct....

Period correct blower......

That’s a lot of dough for 225cfm!

[canuc]

Tuner no doubting that but do they look like a 70's head ? I've never looked at them I think they might have the 12 bolt intake ??? I think Rob needs to decide on his choice for heads what crank for his 350 block , and what tire with his 3.73 gear then he could get some better suggestions for the rest.

[rustbucket79]

Displacement is still your friend, with more making your goals easier and even more street-able.

In the early 90’s I beat my brain out to achieve 12.7’s in my 79 Rally Sport with a 327. A few years later I built a 406 with the same solid cam and top end (Iron Bowtie heads) and ran a 12.1 the first time out in a 79 z/28 using 3.42 gears rather than the 4.88’s I had in the RS. I tuned that combo deep into the 11’s, then with a solid roller and more compression I was in the 10.7’s range.

Since you pointed out you are well heeled, build a 400 to 434 with an aftermarket block and top it off as you see fit and you’ll have a rocket.

I too love the second Gen Camaro’s.

[Tuner]

Tuner no doubting that but do they look like a 70's head ? I've never looked at them I think they might have the 12 bolt intake ??? I think Rob needs to decide on his choice for heads what crank for his 350 block , and what tire with his 3.73 gear then he could get some better suggestions for the rest.

Dual bolt patterns for Vortec and early style intake manifolds (early model P/N 10051103; Vortec intakes P/N 12366573, 12496820, 12496821, 12496822 or 12489371)

[KnightEngines]

I ran 12's with a junk 350 in a 3600lb hx holden in my youth.
Unbalanced mostly stock 350 with flat tops, hydraulic crane 28x cam, stock Morse chain, stock pushrods rockers etc, lt1 springs.
Junk smog heads, 76cc chambers, 1.94/1.5 valves & home porting (before I knew what I was doing), torker intake, 650 holley, 3000rpm converter & 3.36 gears.
I doubt it made much more than 350hp, if that.

Telling this guy he can't run 11's with good 292's, solid cam, proper intake, 30 more cubes, bigger carb, more stall & more gear in a similar weight car is just plain stupid.
Give me those parts today & I'd be in the 10's.

[vortecpro]

YES

[6.50camaro]

This might get long winded but please bare with me, I tend to run on sometimes.
The first motor I had in my car was a std bore 350 no machine work done to the block at all . It was a GM replacement block with under 5k miles . Just deglazed it and put in a set of Icon 11.0 to 1 forged piston . Ancient Brownsfeild heads as cast that were around 200cc .Edelbrock rollin thunder hyd.roller cam 234/238 @ .050 .539 I/ .548 E lift 112 LSA not the best cam in the world . Edelbrock Performer RPM intake 750 DP holley 1-3/4 headers , 2-1/2 exhaust w/x pipe pypes m80 mufflers . th400 tranny 3500 stall converter,4.56 gears Hoosier Q/T Pro DOT slicks . the best I did with that combo was mid 7.50's in the 1/8th which is around a 12.00 1/4 with full exhaust . This is a 72 camaro at 3200 lbs. add 400 lbs. for his car and it would be mid 12's . I never fully dialed this combo in as I had another engine on the stand waiting to go in .
This was my first attempt back at a street/ strip car after over 30 years away . It took me half the summer to get there. Relearning chassis adjustments and launch style the car liked . Nobody has mention anything about chassis set up which could really make or break the OP goals. I have another S/S combo that went in the car after this motor if anyone is interested, it was a 383 with ported 292 heads that went 7.20's in the 1/8th in street trim. Dan

[vortecpro]

What you have in this day and age is............people don't want to do the work for the most part, which in turn never really gave them the opportunity to succeed with a given combination. What I've found over the years, either people can utilize parts, or can't, but that doesn't stop them from being a drag racer.

[PRH]

I started racing in 1979.
At that time, I don’t recall very many “late model”(for the time), 3800lb, sb powered cars that would “drives great on the street” (as was mentioned at the beginning of the thread) that were running 11’s.

My vision of that is a car someone drove to the track, ran 11’s, and drove it home....... no muss, no fuss.
When I was still driving my car to the track(2hrs each way) it was running high 12’s.

Back then, 3800lb mild mannered small block powered street cars running 11’s were pretty uncommon where I raced.

[ClassicRob]

So let’s start over. Would a goal of 12.70 be more realistic for most of you old timers?

[PRH]

At 3800lbs........ the difference in power requirements for a 12.75 vs an 11.75 is about 100hp.

Just build what you want, the way you want....... and it’ll run what it runs.
In 1977...... There was no internet, loaded with car forums and you tube videos to glean advice and instruction from.
There were way less aftermarket parts choices, less shops equipped with dyno’s and flow benches.
Less information available to the public overall.

I read some magazine articles, talked to people at the track....... formulated a plan...... and built my motor and stuck it in the car.
After you went to the track...... that’s when you got your “report card” on how well you did.

The first combo only ran low-14’s with ex manifolds, street tires, 3.23’s, and a 12” converter.
A few years later, changed to: open headers, 3.91’s, 11” converter, old slicks.......ran 12.80’s.

A few years after that I started to appreciate how important the heads were.
So a friend who worked at a machine shop showed me how a few of the machines worked, and I installed some over sized valves in some heads, and tried to copy some bowl work from a magazine article.
Along with the new heads I installed a pretty healthy solid cam I had picked up from a garage sale for $20. It was a Racer Brown that had been ground in 1972, but was never used.
I also swapped the converter for a 10” unit and put 4.10’s in the rear.
Went 12.00@112.

Wasn’t good at all on the street with that cam in it though.
It had a 105 lsa that really didn’t like the exhaust being closed up.
Ran great with open headers though.

I ended up replacing that cam with a smaller Crower solid, which ran great on the street.
It was about .15 and 2mph slower at the track though.

That’s was all with a 440 Mopar in a 3600lb B body.

What I’m getting at is....... the best way to learn what works is to get your hands dirty.

[Rick!]

I ran 12's with a junk 350 in a 3600lb hx holden in my youth.
Unbalanced mostly stock 350 with flat tops, hydraulic crane 28x cam, stock Morse chain, stock pushrods rockers etc, lt1 springs.
Junk smog heads, 76cc chambers, 1.94/1.5 valves & home porting (before I knew what I was doing), torker intake, 650 holley, 3000rpm converter & 3.36 gears.
I doubt it made much more than 350hp, if that.

Telling this guy he can't run 11's with good 292's, solid cam, proper intake, 30 more cubes, bigger carb, more stall & more gear in a similar weight car is just plain stupid.
Give me those parts today & I'd be in the 10's.

From a 12.99 to a 12.00 is about a 100hp difference, assuming the 12.00 car is set up properly with slicks. If set up poorly and 200lbs heavier, add another 25-50hp or so. 450hp in a sbc back then wasn’t real streetable, IIRC.

[PRH]

These were supposedly the original heads off a 69 z28 that was getting restored.
186 castings.

They had been done before...... which you have to expect when they’re 50 years old.
They came to me with the radiused valve job, 2.02/1.60 valves.

Tested at 28”, 4.00 bore, no tube on ex:
As rec’d:
Lift———I/E
.100—- 66/48
.200—-121/90
.300—-170/111
.400—-200/124
.450—-207/127
.500—-215/128
.550—-218/129
.600—-219/129

67E54D96-223D-43B3-8F91-E80397B860D5.jpeg

After installing hardened ex seats, recut seats, blend bowls and SSR:

Lift———I/E
.100—- 68/50
.200—-133/98
.300—-186/129
.400—-216/157
.450—-219/162
.500—-223/166
.550—-228/168
.600—-229/168

6AFE2628-C554-433F-B9C5-F83597C706B6.jpeg

Should get to 400-ish hp on pump gas without a cam that’s too gnarly.

If you were on the “best ET” plan, you would use a pretty big cam, Victor Jr(shooting for 450hp), plenty of stall, plenty of gear.
But then it wouldn’t be nearly as street friendly.

A 25 year old me would have been fine with that.

[BLSTIC]

Just remember that we now know about port energy, carb boosters, stepped headers, texturing, and so on. Even if you don't get much more power than way back when, you can get a lot more drivable and mid range for the same peak power.

Could you fabricate your own intake manifold? Plenty of that going on in the 70s so that's still period as long as you don't start alloy tigging things together

[BLSTIC]

Quote from another thread:

In 1970 the factory Boss 302 mustangs in the TRANS AM series ran an intake manifold where 1 cylinder was connected to one barrel of the carb . Twin 1150 dominators were used. YES two 1150 dominators on a 302 cid engine.

Is this an option for a period SBC? I imagine tuning would be... fun... but individual throttle carbs generally have decent response and mid-range.. It also adds to the impression ratio when you're at a show and someone opens the bonnet to see that much carb.