Steve, my 1995 K1500 Cowboy Cadillac.

[Supercharged111]

I use a late 80's 454 TBI adapter, which GM used for a couple years when they used TBI on the GMT400 big blocks but before they developed a new manifold design. But the 454 carb pad is a bit different shape and I had trouble making sure the sides were properly sealed.

Ahh, so late MarkIV engines would have used that adapter? 88-90ish?

 

[MIHELA]

Yes. This is basically a Quadrajet intake manifold to TBI adapter, and a well designed one. It has a heater circuit which I use, and a brake booster port.

 

[Supercharged111]

Yes. This is basically a Quadrajet intake manifold to TBI adapter, and a well designed one. It has a heater circuit which I use, and a brake booster port.

Nice. I never knew that was a thing.

 

[Erik the Awful]

Your plenum is still below the intake ports and your intake charge is having to make an s-curve to get into the engine. The Edelbrock Performer for Cadillacs is the best streetable intake, but they're a bit pricier now than the $300 I paid for mine.
www.summitracing.com/parts/edl-2115/make/cadillac

 

[MIHELA]

The Performer is still not ideal. I would have to fab different brackets for AC, I would lose low end torque, and what I really want is a multi-port injection setup down the road. I would like to fab up a new manifold. I mainly got the 368 manifold for weight savings. It weighs 17 lbs vs 46 for the iron dual plane. I also get slightly better fuel economy with it.

 

[HotWheelsBurban]

The Performer is still not ideal. I would have to fab different brackets for AC, I would lose low end torque, and what I really want is a multi-port injection setup down the road. I would like to fab up a new manifold. I mainly got the 368 manifold for weight savings. It weighs 17 lbs vs 46 for the iron dual plane. I also get slightly better fuel economy with it.

I will vouch, the stock 472/500 cast iron intake manifold is a boat anchor. Picked mine up, moving things around to see what all I have, and I'd forgotten how fricken heavy it is!

 

[1ton-o-fun]

EXCELLENT door stop though! Lol!
I'm going to use the Performer on mine.

 

[Erik the Awful]

Back when my 472 was still in my '69 I had to replace a head gasket once. To remove the intake I had to reach about 3/4 of a mile into the engine bay and lift it out. Then I had to reach 1/2 mile in and remove the 62 lb head. That sucked, but I was young back then. I wouldn't want to try it now. I can't sit in the engine bay of the Caddy like I can the truck.

 

[MIHELA]

Nordstrom's 14th Annual Harvest Day was yesterday. I got a couple new dash bezels, some radios, a pile of mode actuators, a headlamp harness, new headlights, and the mounting bracket on the passenger side for mine which has been stripped for so long. I got a working dome lamp switch for the passenger side so that works again. The old one was melted! I also snagged the homelink module from a 2015 Impala that I'm going to piggy back into the old one so it can run my new garage door.

 

[Erik the Awful]

So, I finally read all the way through this thread today, and I think I have an answer to one of your questions.

Installed my shaft rockers today.

I bought them from a member on Cadillac Power Forum. They are an older design, not sure who made them. They are similar to Stage 1 setups currently made by Cadco.

They look identical to Maximum Torque Specialties' 'budget' shaft rocker setup that Al Betker used to sell back in the day. I bought mine for about $400 if I remember right, and immediately after he sold the company to the two dudes from California, the price jumped to $700. Without the shaft setup, you're limited to about 4500 rpm before they start falling off the pedestals.

Just to note, the stock rods are good to 5200 rpm with ARP rod bolts, and 5000 is a safe rev limit. At 5400 rpm you will lose rods. They're well built, but 5400 is their limit. Stick to below 5000 rpm.