My 74 Mav Grabber has stock 302 with the exception of 4 bbl, dual exhaust & MSD Distributor. My question is this. Is it practical to put Aftermarket Aluminum Heads on a daily driver? It's not really a daily driver. I drive it to work about 1 day a week (1/2 hour each way) just for fun. I would just like it to have a little more get up & go! If I change the Heads do I have to change anything else, Lifters, Push Rods, etc.? If this is feasible what heads do you guys recommend?
That's a broad question with many possible answers. First off, what is your budget? How much, and not a penny more, do you have to spend on go-fast equip? Will you be doing the work yourself? Do you have enough experience/tools to do the job yourself? How quick do you want to go? Will you be racing it at the track? 1/8th mile? 1/4 Mile? What gears do you have now? I'm not trying to be a smarty-pants, but Fast=$. How much you have to spend is going to help determine what's the best bang for your buck. At some point, you get deminishing returns. AFR 185 heads used = ~ $1000-$1200. Then you'll want hardened push rods, aftermarket roller rockers, headers to let the heads exhaust, sufficiently sized carb to feed 'em, better flowing intake to let more air in, and so on and so on and so on. But again, the first question is how much do you have to spend on go-fast parts? Maybe a simple gear change will be sufficient for now.
Rick I answered your questions above. I understand your point. I want this car to be very streetable. I will not be running it at the strip. I just want to make a nice improvement in it's performance. I was hopeing the Aluminum Heads would be a good streetable addition. I have a 73 Grabber that I'm thinking of making Street/Strip.
You can build a car that can drive any where and still go fast. Mavaholic, Riporter, myself, and many others here all have fast,reliable, and very streetable cars. It comes down to being smart in your selection of parts. Build it to make power from 1500rpm to approx 7k. A good set of heads and valvetrain components, Compression around 10to1 to 11to1 and a cam to use in that workable rpm range. Just throwing a set of aluminum heads on will leave you disappointed. It is a package type deal. A purpose built motor. Otherwise I agree a set of gears would help 3.40s to 3.55s. FWIW I will fire mine up and head any where any time. I run in the 12s. Dennis' and Ricks cars run very similiar numbers and I am fairly sure those two will drive any where too. But they can pipe in for themselves...
Most OE engines have run aluminum heads for years now so the material isn't an issue.But for mild performance upgrade just grab a set of E7's or some GT-40's & slap 'em on.But as Lance said,it's a package deal,you just can't throw parts at it without looking at how they work with each other.The E7 & GT-40 heads should work well with your limited mods and can be found used reasonably cheap.
I will buck the trend here... Aluminum heads will remove a little weight from the car and can handle a little increase in compression without increasing octane. I am not saying that you will be satisfied with the difference while keeping your 2.79 gears. However there are positives to hauling around less weight and bumping up compression a bit with small chambers. Put it in perspective: Iron heads with no other changes = small increase with same weight and compression. Aluminum heads with no other changes = small increase with an increase from less weight and a decent bump in compression. Not to mention a slight economy increase from weight loss. Then, if you intend to make other changes as well, the aluminum heads just magnify that further or give room to make more changes later. Just my .02 Dave
I'm with the others on here. It needs to be a complete package. I have GT40 iron heads. The heads alone did a little but with a better cam & 3.55 gears & posi unit & Airgap intake & 600 carb, I thought I had a new car. Huge difference over stock. If you get a good set of heads than the cam has to have enough lift to get you in the airflow of the head.
My two cents, if you do regular interstate highway driving, I wouldn't touch those gears...leave the 2.79 in there. I could still break my open 2.79 gears loose with the original all-stock (except for intake) motor. But even the 2.79 was a little uncomfortable on the highway with high rpms at 70mph. If this car is not going to see the track, I would leave the gears alone. It seems that you could still do some really nice modifications to the motor, and still take off pretty fast, but you would never live down the gear change if you are doing regular highway driving. Now, if you even do a little racing, go with 3.55, still not screaming down the highway, but quicker takeoff. I have 3.80 and do interstate driving, but I seldom go over 60mph, in a 70 speed zone. I don't like running the car at 3750-4000rpm for long periods of highway driving, but I DO like to take off really fast. I can get to 80 mph in around 5-6 seconds, but I don't stay there for long. I can pass that Mustang up pretty quick, but then, after showing off (just to keep him on his toes) I then back down to 60-ish and just take my time. I don't think you want to drive like that if you do regular highway driving. A gear change would eat you up.
I dumped a 3:55 in favor of a 3:00, just for that reason. I do a lot of highway driving in my car, and the 3:55 will spin the engine up too much. No sense wearing it out before its time.
There are times when I wished I would have bought a second rearend, or center unit, and swapped them on days I raced. I used to race maybe 4-6 times per year, until my local track closed down. I really wish I still had the 2.79, then I could just swap them out a couple times a year, especially now that ALL my driving is highway and some in-town stuff. I have to admit, the 3.80 posi is kinda nice for some of the in-town stuff, especially taking off from red lights :evilsmile
I was very iffy on this myself, several of my friends finally convinced me that well made aluminum heads will disipate heat better and wont flex as much as cast heads. that played more of a factor in my switching to trick flows than just the flow numbers and chamber size. of course that all still factored in, but im definately not taking full advantage with a radical cam because i do plan to drive it on the highway.
If I could do it all over again, I would go for the best heads I could buy the first time. In my case the GT40Ps are about what I can afford, but I would have done them sooner. Even if I did not see the improvements with the heads, I would have seen them with the other modifications. I am a tinkerer, and I love to mess with things, or replace things, and see what kind of improvements I get. If I had better heads to begin with, I would have had better results from my projects, and I would have bought higher-performance parts the first time. Since my heads were stock, I knew that high-dollar intakes, cams, etc. were not going to show me much gain, so I bought mid-range parts. I wish I had the head-flow to begin with so that I would have gotten parts that were a little more high-performance the first time around. I feel like it is setting a better platform to start building on.
I just noticed that you say "money is not an issue"... If so, get your 3.80-4.11 gears with locker, then put a Gear Vendor on your tranny. You can have your cake and eat it too. Just switch the O/D on when you get on the highway, off when you get on the street. Dave Edit: I should tell you though that you wouldn't want a gear unless you had a cam to match your new heads. Otherwise you would rev out of your cam's rpm range too fast and you would get the sensation of driving a truck rather than a fast car.
