600hp with exhaust manifolds?

We did some dyno testing a few years ago between the manifolds and a set of 2” headers and it was a little over 40hp. We knew the manifolds were going in the car,but we were wondering at the time. It was a sleeper 494,hyd roller,pump gas,looked like a stock 1970 engine on the outside. Power differences would vary. We were very conservative on the cam. No intake or head porting.

 

Tom Righter did something to his iron manifolds that really improved his ET and MPH.
Check with him.

 

I’m getting a lot of good information. I appreciate all the help that’s available on this board

 

Here is dyno with 1 7/8 headers.

 

ours were 482s, single plane, 10.6 compression,hyd roller. Heads flowed high 330's on intake. the higher compression you want will sure help.

 

If you could get a nice built n.a. motor and spray it you could make 600 petty easy. You may need race gas to spray in with the nitrous.

 

Thanks Larry

 

How much do you think I would lose using a B4B?

 

Larry, I’m liking your advice on the TA510 vs Window Rattler. If I did my math right I could run 11.4:1 with the 510 compared to 12:1 with the 107. I wouldn’t have to cut heads again with the 510. I would be right a 8:1 DCR with both cams. I used 470 bore n stroke. 21cc dish. Head gasket .030. 4.4 gasket bore. 59cc chamber for 107,64cc for the 510. Both cams advanced 4 degrees. Any idea what the power difference would be?

 

I think you will run into a compounding problem........the manifolds will only ever flow x amount.........if you try to pass more through them, the restriction they make will just grow.

So let's say a combo with headers and all going from cam a to b gains 20.......but on a the motor with manifolds you might only get 10......so going from cam a to c on the 1st motor might gain 40 .......on the same motor with manifold you might only gain 15 from the same cam swap.

The more you try to shove through there, you going to keep getting diminishing returns at some level......yes it might even get to spot like in a cylinder head....going to big of lift gain nothing or even losses flow and power.

Is there anyone in the area that can make you custom headers.....won't be cheap, but very well might be worth it.......I've done a few sets for vehicles we couldn't get an off the shelf part in........mine didn't look the best since I have no training and not all the correct tools.....but they did fit and not leak

 

Thanks Larry. I got the same numbers as you when using 12:1. I was using 11.4 with the 510 to get 7.98 DCR. I would feel more comfortable with the 510 at 7.98. I’m not sure I have the skills to get the tune good enough at 8.38

 

What about some of the shorty headers available for Buick? They are not a long-Tube or equal-length headers,but would make more than the iron logs. What car are you installing the engine in?
Yes,you are going to choke it down,even with ported manifolds,so if you have a build that makes 650-675 with headers,you should still be able to make 600 with manifolds. This is very achievable with today’s parts and camshaft technology.

 

I’m a pretty good welder and have enough tools to fab some headers. I don’t have enough patience. A buddy of mine has made a couple sets. He is a bit pricey. If I stay with my current car I already have headers. I’m just lacking power.

 

I have an 80 Cutlass with a 462 putting out about 450hp. I’ve been looking at a S-10 or maybe a Mustang. I’d really like to find a nice Regal. Problem is my Cutlass was $500. A Regal in the same condition is a $2000-$3500 car. Can’t figure it out

 

The Regal and the Cutlass are the same G-body chassis. There are headers available for a 455 in a G-body. The S-10 will likely take some fabrication or modification of existing headers. The Mustang will definitely take some fabrication,but the shorty header might be less headache in that situation.
If you like your Cutlass,stay with it. You already own it.

 

If we wanted things cheap and easy, we would not be Buick people.

 

Just be glad you’re not Oldsmobile people. They will complain even if it’s free.

 

I would not try to put a 455 in a S10 they have to do all kinds of things to fit the SBC. The mustang would be all kinds of work as well. Unless they are tube chassis with motor plates it would be more work than its worth. The cutlass you could swap the front end to look like a regal.