Alright, I have finally decided to go ahead and get some new heads and cam for my 75 L48. First Ill give you a little background as to what I am running right now for comparison:

Stock heads, Valve Job and milled
Melling MTC-1 cam 204/214 dur .420/.443 lift
L82 Aluminum intake
Holley 4175 650cfm carb
Stock HEI
stock rebuilt bottom end
stock ram horns
74 dual exhaust with Mid America Turbo Mufflurs
4 speed close ratio trans

I took the car to the drag strip and was able to run a 15.90 @ 91mph quarter mile with this set up with some very bad starts I must admit. Probably a mid 15 sec car with a little practice on my starts. Now Ive got the bug and I've been really wanting to do something to increase the power so this is what I've come up with:

Brodix IK180 64cc chambers heads, .015" gasket for about 9.75:1 compression
Lunati Voodoo 60102LK cam 219/227 dur .468/.489 lift 1400-5800 rpm
L82 Aluminum intake
Holley 4175 650cfm carb
HEI w/ 50,000 volt coil from summit
stock rebuilt bottom end
Ill keep the stock ram horns for now and the exhaust

So these are my questions:
1. What do you guys think of this set up, cam to big or small
2. What kind of power can I expect from this set up
3. Anybody have any experience with a similar engine package
4. Will the stock temp sending unit work with these heads
5. What length pushrods should I use
6. Will the thin gasket be ok or should I sacrifice compression for reliability.

Sorry for having so many questions I just dont want to drop a bunch of money into the car that wasnt worth it. You guys seem to really know what your talking about so any advice would be greatly appreciated. My ultimate goal is to get the car running in the 13 sec range but really still maintain good driveability because I drive the car alot in the summertime. If theres any information I left out just let me know.
Thanks in advance.

~ Joe

 

A frequent first response is "Use the search". I have a 74 w/similar set up.

TFS heads
218-224 HR .532-.539 w/ 1.6 rrs
Air Gap Demon 650
Rams Horns 2.25 w/ H pipe

280 rwhp 315 rwtq

I know the RHs are holding me back after 5K. I am very happy w/cam.
You need better heads or less cam. Vetts love 1.6 rrs.
You get .030+ extra lift for min gain in dur. The engine runs much cooler w/AC on, which is the real test for your cooling system.
I have 3:55 gears/M21 and get 20 mpg Hwy.
This combo has BB mid range, it really pulls.

Ricisan

 

So you dont think that the brodix heads will flow enough for that cam. I really want to stick with the brodix heads for budget constraints. What cam would you recomend for those heads. I want to keep the cam heads and lifters under $1200. I will also be using headers eventualy.

 

Hi Joe
Iv'e got that cam in my 350 with 292 angle plug heads which would be about the same as your suggested heads. I feel that my cam is too small, even with a stock TH350 & convertor. It does not have a lope at all. The cam should be larger in duration say 225/235 and lift at .500" or better, use 1.6 rockers to compensate if needed. Use an air gap manifold with a 670cfm Holley Street Avenger or the 4175 if you want.
You could expect around 360 hp out of this, and it should get a high 13.

 

there are better manifolds out there..I wouldnt go above the 500 mark on the cam..jsut to live with it,. 315 horse should get you very near the flat 14 second mark.

 

Along with adding a little HP, you really need to think about gearing. A close ratio Muncie, assuming that's what you have, has a 2.20 ratio 1st gear. Your rear gear is probably 3.55 or lower (numerically). That combination will limit your 60 ft times. Don't forget that any improvement you make in 60 ft is usually doubled in 1/4 mile ET. Take a tenth off the 60 ft and run 2 tenths quicker ET overall. If you add a hotter cam which moves your torque curve to higher RPMs, your need for more gear will be even more pronounced.

 

I would try another intake....

 

I think it looks like a pretty nice combo.
There are things I might change if it were me, like the intake & exhaust manifolds, but overall its not bad.
As long as the .015 head gasket is the coated type, & not just a plain steel shim it will be fine.
I bet with some tuning that you could run some 13s with the combo.

I just looked at the specs and the cam you are thinking of running is one cam smaller than the one that I was thinking of.
You might look at the 60103.

 

J.Aro75Vette:
What about the pistons?
Flat pistons: you will be at 64cc with the 0.015 gasket CR ~9.7.
Dish pistons: you will have more cc at the combustion chamber and the CR will be lower.
Avner

 

You picked a good combo of parts the IK180 brodix will flow all the air a low rpm hydraulic cammed 350 will ever need, the cam fits well with the amout of compression you will have to work with.
JustinD on the forum has the FPP-1094 .015 gasket with his aluminum heads has had no problems with the gaskets. original factory gaskets were .018 steel shim gaskets, so no reason why you cant run stock length pushrods with the .015 gasket.

Comp cams has heat treated, welded tips, stock length pushrods needed for the guide plates on the brodix heads #CCA-7812-16 $29.95. www.summitracing.com.

Brodix made its first aluminum head in 1969 for a 426 hemi, yrs and yrs of working with aluminum building heads for race engines and street engines.

 

it would be cheaper for you to go vortec heads/intake than the combo you listed, plus you would get much more hp and torque! i did this to my '77 L-48, and how i have 300hp/345tq at the wheels! look at jegs for a great deal on the heads, and get a professional products intake (new or used). it' worth every penny...

 

Vortec heads are good heads, but they are NOT better than the Brodix IK 180s

 

I don't work for Brodix not selling there heads but the tests I have seen on airflow and horse power on the same engine the IK180 was considerably better then the vortec head. If your buying new parts after you have to buy a different manifold to fit the vortec head, different valve covers, I think the rocker arms are different. the $1013.00. brodix setup will be right at the same money, you end up with a better airflow head save 33 pounds of weight.

 

Thanks for all the responses everyone.
I would go with the 60103LK cam specs: 227/233 dur .489/.504 but I was worried about having to turn the 2-bolt block 6200 rpm in order to hit its limit. The other cam max is 5800 rpm and I really did not want to turn it any more than that. I also would go with a better manifold but I didnt want to drop any more money into the car than what I was already doing. The way I am looking at this project is if I do the heads and cam right and I dont have to touch them agin I'll be happy. I can always do an intake swap and headers later. I just want to get a good base to work off of.


Avner- The pistons are dished but I still got a 9.75:1 comp ratio using an online calculator. Does anyone not what cc the dish is. I used -13.

Also I'm not positive on my rear gears but I believe they are high(numerically) because at about 50 mph I'm doing a little above 3000 rpm.