Modified 67 Riv - combo critique

Hey Buick fam,

Picked up a nice 1967 Riviera and the previous owner did some work to it that has me scratching my chin. It's got the following ;

455, .030 over
poston sp-1 aluminum intake
forged pistons, around 10:1 compression
stage one heads
HEI distributor unknown make, 7* initial timing, mechanical advance unknown
Stock qjet
Stock exhaust manifolds
3 in dual exhaust
Riviera GS posi
PAE switch pitch 1400 low / 4000 high converter
TA 290-94h cam

It idles...alright. I'm thinking I'll need to bump up initial timing, idle and I'll do a vacuum leaks check with a smoke machine. What do you all think of the converter? Seems a little too low and a lot too high. Not sure but I feel like with a lot of these parts it should feel a lot more powerful. Suggestions welcome.

 

Lots going on here. I’d start with Larry’s Power Timing Thread. Read that over and over till you fully understand it then ask more questions. lol. It’s kinda like that. You came to the right place though. I’m sure others with more knowledge will chime in.
Cliff

 

Thanks Cliff! I've been reading the power timing article and I think I'll need to bump up the timing a few degrees. Trying to confirm how much mechanical advance is built (possibly 20 degrees) in to the distributor, I believe it's adjustable.....

Wondering if I should ditch the current switch pitch. It doesn't work right now and is defaulted to the low 1400 and I believe that is a smidge too low for the cam that was installed... possibly.

 

Find out why the converter is not changing stall.
Easy to test using a 12v power source to the case plug on the driver's side to see if the solenoid works and the converter changes stall.
If the solenoid "clicks" use a toggle switch and then activate it when you drive it to see if it stalls properly.

Then you can figure the carb/brake switching and get the converter working as it should.

Otherwise, you are going to be pulling the tranny and pump to swap it to a non-switch pitch pump/converter, or paying to rebuild a switch pitch converter for higher stall as the hub and splines are different between a switch pitch and non switch pitch converter and input shaft or rear section of the pump.

When the TH-400 was prolific, getting a pump and converter were easy and cheap.

Yes, that "all the time" 1400 stall turns your powerboat into a tug boat. 4000 would be great for launching and downshift/WOT while the 1400 would be great for cruising if you can get it working.

 

I've heard some not-so-great things about the PAE converters. Might be a something to research...

 

If it's a single plane "sp1" it's a TA intake...the Poston is the "S divider"...it's not a popular choice for a few reasons...but works in that it's an intake manifold

Put as much initial timing as you can...check the distributor # and add the initial you need to achieve 32~34° preferably in by 3500

I would probably ditch the trans all together and have a fresh th400 done with a 2800to3200 stall

 

Ah! Yes my mistake, it is the s- divider intake. Guess I'll do some more research on that, thanks.

Yeah have to figure out what to do with the trans. The car came with a stick 67 switch pitch converter but I'm not sure that would be any improvement over the PAE....

 

I just had this conversation with Jim Weise, Tri Shield will still build performance switch pitch converters using your core. I have a converter I suspect is a PAE unit, I'n not gonna use it for fear of throwing metall all through the existing transmission. And (@Jim Weise correct me if I'm wrong), it wont make a suitable core due to internal modifications)

 

I am scratching my Chin also as to why someone would force good flowing heads to pump out thru exh manifolds and forfeit any possible gains in power from higher VE .

here’s a good way to set up a HEI.
It allows low initial timing for easy hot cranking .
The drawing can be enlarged once printed off since it’s drawn to scale.

 

Thanks very much for all the great suggestions everyone! After climbing around the car a bit more I have found the following:
1. wires going to the left side of the trans into a solenoid of some sort to be cut
2. what I believe to be some sort of switch pitch switch and cable on the throttle linkage not plugged into anything
3. the entire kick-down and switch pitch assembly normally located on the left side of the carb to be missing
4. paperwork confirming it is a PAE converter
5. a later GM kick-down switch bolted to a homemade aluminium bracket bolted to the electro cruise system on the engine side of the firewall, the kick-down was not working prior and this explains that.

Wow - lots to fix here, but it sure is fun. I'd like to keep the switch pitch and just get a different converter that compliments the cam better. Since the car is missing the stock components I might wire up the switch pitch to the brakes once I get everything figured out.

I had a pair of shorty's on my last 67 and liked them, might pick up another to go with this very nice 3" TA exhaust system on the car.
The S-Divider, from what I have read, may contribute to low vacuum under certain conditions - interesting. Considering hood clearance issues on the Riv would you recommend a stock intake or ....what was the other one? B4B or an Edelbrock one?

 

Man that converter has some booger welds

 

If its the stock 430 carb it will definitely need jettted up for the extra cubes. I would say step one would be to straighten out the converter though. 4k is way too much.

 

Great advice thanks. Well updates:
1. Did a vacuum leak test with a smoke machine - no vacuum leaks but, there was a big leak wherein smoke was pouring out the back of the S-Divider intake - that explains the oil on the back of the block. I ordered up a nice used Performer intake to replace this one. No other leaks evident
2. Revisited timing. Unfortunately have no idea what kind of HEI distributor this is but the car is behaving nicely at around 7 to 8 initial timing with whatever mechanical advance is at.
3. Will pickup some Riv specific shorty headers to compliment the heads and exhaust.

Still working through the switch pitch and downshift madness I discovered. I think I will swap in the stock 67 switch pitch and run that instead of the PAE 1400/4000 unit, and retrofit a downshift switch to the pedal.

BTW I have three sets of Riviera brake drums for free if anyone wants them (front, rear and an aluminium front set). Plus a bunch of sbc 350 stuff - cleaned the garage out. NW side of Chicago.

 

Ditching the S-Divider is definitely a smart move. Using an open spacer is a crutch to overcome the lousy distribution inherent in it.

As for shorty headers, I think they will help and are about your only option.

 

I’m running that cam, Performer intake, 800 cfm Qjet, 2200 converter, ported exhaust manifolds, 2.5” mandrel bent exhaust, and have a distributor that’s 32* centrifugal by 3000 rpm. it idles rumbly at about 800 in gear. Pull well, loves 3.55 gears, goes high 12s in a ‘68 GS.
As for your combo, swapping the S-Divider for a dual plane is a good idea. Sort out the converter. 3” exhaust is overkill. Curve the distributor. Tune the Qjet.
Rock n Roll!
Patrick

 

Very encouraging. Still working out the timing but I'll get it right. Hey PBR400, what type of 2200 converter are you running? I was playing with the idea of nabbing a Holley 870 Street Avenger I see used for sale to top off the combo.