383 with a 471 blower

[67charger383]

Found this picture online, it's a low deck 383 or 361 (I forget which) with a 471 blower on a tunnel ram base. How stupid would it be to do this? Already have a 383 tunnel ram...

 

[493 Mike]

Impress your friends!
Mike

 

[Don Frelier]

For a "low deck" that is quite tall.

 

[PROSTOCKTOM]

In my opinion it would look really stupid when you consider the center of the blower pulley will be at the hood height.

Tom

 

[Woodruff Carbs]

4.71 will improve performance up to around 300 cubic inches. Those were used to pressurize the crankcase on Detroit diesels.

 

[MiradaMegaCab]

https://www.aussiespeedshop.com/product/as0290-gm-671-tunnel-ram-base-plate/

Go big or go home. Get a 6-71 or 8-71. That 4-71 pictured looks to have a 1:1 drive ratio. It’s not gonna be making any boost on that engine. Perhaps only for a moment during WOT off the line acceleration.

 

[Budnicks]

be great in a ratrod

I remember a guy in Concord, Steve
he had a 64 Falcon/Sprint, full cage, tweed interior
4:71 Blown 289 2 x 390cfm 4bbl holley's IIRC,
on an iron 4 bbl factory intake home made pop off valve in the back
IIRC with a 1/2" alum adpt. plate for the blower, offset distributor drive
it ran at like 5%-10% under-driven, sounded pretty good, bright yellow
back half'd, narrowed, tubed, stock type leaf springs, shitty shocks
14 x 31's IIRC old Mickey Thompson S/S sticky treaded tires/hard as a rock
this was real early in the pro-street days (1979ish - early 80's)
typical show car deal, all show no go

he really wasn't a racer, more of a-typical show poser,
always that guy that sits by his cars at shows
& talk **** type, like he was bad-***, because he had a blower
rarely ever used it like it was intended
I'm sure you know the type

but we talked him into going to Fremont Raceway,
to actually run his car, I was there for a test & tune Sat.
he had a 3" belt drive just like my altered,
I loaned him, like a 42 tooth top pulley, to try,
he had like a 52 tooth IIRC
it sounded really good, pulled the plugs & was really lean
he changed the jetting up like 6 jett sizes
made a pass 13.50's @ like 99mph, sort of sputtering a little,
about what I figured it'd run
he took way too much timing out
he was paranoid he'd blow it up
we advanced to the ignition to about 32* IIRC,
IIRC it was at like 26*
went out made spinning off the line,
a 12.20's pass @ like 118-120-ish IIRC
we were all totally shocked
for a 3200# (?) car with a mild 289 forged pistons,
a like .450" lift hyd. cam
with a few bolt on goodies & headers in/on it
& a good fresh GMC 4:71 blower & just a few % overdrive
with very little tuning

I told him I have a like 10 tooth bigger pulley he could put on the crank
than he had, to get like 15%-20% overdrive IIRC
BUT; he wouldn't do it
I think with decent traction & a few more #'s of boost
he'd been in the 11.90's easily
I doubt that thing without the little 4:71, would run in the mid-hi 14's

Anyway;
he made like 10 passes that day, never really got much better
started launching a little better, but never got better than the 12.20's
it was consistent as hell, even spinning

I admit he did better than I'd have thought he would have

just thought I'd share,
cool story about a 4:71 blower, in use

 

[PRHeads]

At the track I used to run at all the time, just over the Canadian border, was a guy who would show up every once in a while.
The car, a Dart, looked like it had probably been a S/G car in its earlier life.
Full cage, lexan windows, tubbed with like 14x32’s on it.
It had a low deck something in it.....383, 400, I dont know.
It had a 6-71 on a home made plate, that was bolted to one of those low deck 6bbl manifolds.
The only reason I’m sure that’s what it was is because I wandered over where they were parked when the blower was off it one day for a look see.
One valve cover was off too....... all stock stuff in the valvetrain.
It even had the lo-po springs with no dampers.
Black and pretty grungy looking too..... like right out of the bone yard.
Two mismatched looking, possibly OE Holley carbs on it, with a fresh coat of poorly applied gold paint on them.

I don’t recall exactly what it ran, but I’m pretty sure it was solidly in the 10’s.

 

[33 IMP]

Please folks, no insult intended to anybody, but....... that looks like a 6-71 to me. The picture angle is poor to show the length of the blower case, but im not sure a 4-71 is long enough to support a set of holleys, sideways or not. I dont recall ever seeing a 4-71 with more than a single holley on it. I did see one with two afb's. The case in the picture seems to be as long as the tunnel ram, and i dont think a 4-71 is.
Just questions on my part , dont mean to be a richard. There is a good chance i'm wruh...wruh....wrong.

 

[Tony Tee]

Found this picture online, it's a low deck 383 or 361 (I forget which) with a 471 blower on a tunnel ram base. How stupid would it be to do this? Already have a 383 tunnel ram...View attachment 961132

That looks bigger than a 471 ???

 

[1 Wild R/T]

Please folks, no insult intended to anybody, but....... that looks like a 6-71 to me. The picture angle is poor to show the length of the blower case, but im not sure a 4-71 is long enough to support a set of holleys, sideways or not. I dont recall ever seeing a 4-71 with more than a single holley on it. I did see one with two afb's. The case in the picture seems to be as long as the tunnel ram, and i dont think a 4-71 is.
Just questions on my part , dont mean to be a richard. There is a good chance i'm wruh...wruh....wrong.

First thing I thought too.... Worked on plenty of 4-71's, 6-71's & V6-71's while in the Navy.... That looks like a 6-71 to me...

 

[1967coronet]

Nothing says 70s like a set of painted red headers
I had white LOL, The old VHT header paint came in many colors.

 

[PRHeads]

Check out the mounting bolt holes

 

[Tony Tee]

Check out the mounting bolt holes

View attachment 963135 View attachment 963136

Looking at the fuzzy picture (when zoomed in) in the original post, it's not a 471? Cause I see 4 mounting bolts on the one side and a 471 should only have 2 ?

 

[Budnicks]

blowing it up bigger,
it looks to be a 6:71,
looks like "it may have 4 bolts" on that side, on the bolt pattern
& it's pretty short drive for a 4:71 too, they tend to be a bit longer

being on a tunnel ram, is what I was looking at & thinking of
didn't pay much attention to the details

still a good story, good discussion

brought a couple out of the wood works, to comment

 

[67charger383]

Listen guys, sorry I got it wrong. Im not a blower expert, the guy I got the picture from said it was a 4-71 but you are right that it's a 6-71. Thx for the education.

 

[1 Wild R/T]

Listen guys, sorry I got it wrong. Im not a blower expert, the guy I got the picture from said it was a 4-71 but you are right that it's a 6-71. Thx for the education.

We won't be bringing the pitchforks this time... But you've been warned....

 

[1 Wild R/T]

More info on blowers.... From the "Way Back Machine"

 

[biomedtechguy]

pitchforks

 

[33 IMP]

More info on blowers.... From the "Way Back Machine"

View attachment 964145 View attachment 964146 View attachment 964155

I know Lowinski and Lovelace. Who is the other one?