I have a small block Chevy 350 installed in my Regal. So far I have a Summit 600cfm 4bbl carb, Summit intake, electric fan and aluminum radiator installed. Im looking to have around 300-350 horses. The motor came out of a 74 C-10 so I think I have a few more parts to go to reach my goal. Im looking at upgrading the heads and rearend pretty soon. Ive been looking at RHS/PAW and the Summit brand heads. Im lost when it comes to the rearend. Does anyone have suggestions on heads and the rearend. Can the 7.5 rearend be upgraded to hold more power?
SBC 350 upgrades....and rear end
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Being that the 7.5 is a touchy topic, I'll leave this very general. It really depends on what you are building the car to do. If you want to drag race it, I wouldn't bother with the 7.5, for the money you would spend on upgrading it to hold up, you could have a ford 9 inch for equal or less money and have a much stronger and upgradeable rear that will hold up for future mods (IE big block, stroker, etc). If building a strictly street car with street tires, the 7.5 can work for you, how long depends on how you drive it. I have had two grenade on me, one was due to severe abuse (prior owner neutral and reverse drops), the other was due to sticky tires, a harsh shifting trans, and 0-whatever launches (the carrier gave up when I shifted into second). The last 7.5 I put in my car, was in for about 2 years, (recently upgraded to an 8.5) I changed my driving style, put street tires on, and never had an issue, (fewer hard launches from dead stop, less burnouts, drove like a human, lol), still had fun with the car, but within reason. By the way the rear was holding up fine when I took it out against a 300 or so hp 350. So can they be upgraded? Yes, but is it worth it? That all depends on your driving style, and if you plan on putting more power to it in the future. In all honesty, why build it twice? down the road if you decide to put a really stout engine in, you will need to ditch the 7.5 for something better, if you have a grand tied up the 7.5 rear already, it is a waste of money, because you'll never get that back out of it. Spend a grand now on a decent rear (9 inch, 12 bolt, 8.5) and you'll have have a worthy set up for for future additions.
I agree. I have about a 350hp 355 with a 7.5 that has a spool in it. I have drag raced it on 9 inch wide street tires and I havent broke it yet. But its just a matter of time. I have heard the 8.5 will take a considerable amount of power. But the ultimate would be to have a ford 9 inch. Not to mention if you break and axel its not gonna tear the whole side of the car off. A great head for that motor would be the vortec head. My dad built a motor for a dirt modified at 12 to 1 compression a fairly large cam and the vortec heads un ported made 538 hp ohh and it was 355 inches. So I think if you did a cam upgrade maybe to a comp cams XE268H the vortec heads and maybe an edlebrok rpm airgap manifold (since you have to run a different manifold with the vortec heads) and you should be good to go.
I figured I would have to upgrade the rearend eventually. I dont plan on doing any racing but I may open it up everything now and then. Is the Ford 9" an easy bolt-on or is there fabrication involved? If i knew the Vortec heads required the Vortec manifold I would have got the Vortec manifold. I currently have the Summit Racing Stage 1 manifold. Heads, Cams, and lightweight pulleys are my current goals right now.
The problem with vortec heads is that there is a lot of machine work involved. You have to machine the guides to handle any aftermarket cam and you will need larger springs right out of the gate. Edelbrock makes an intake to match the vortec heads. But with the cost of machine vortecs, you might as well buy aluminum. I'm running a set of 333882 heads that have 2.02/1.60 valves, no shaving on block or heads, and I paid 400$ for those off ebay about 4-5 years back. Never had a problem with them and they are great street performance heads. IMO most of the aluminum heads are all the same and share a lot of the same specs. Your just paying for the name. Why do you think edelbrocks are so much?
As far as rearends, I love the 7.5 and the 7.625 I have now out of a 86' monte ss, 3.73 gears. I had that rear end rebuilt with new yukon ring and pinion for about 300-400$. Now if you have a really serious setup, then yes a 9inch or 12 bolt will be best. I think the 8.5 is just a happy median and people are charging stupid money for them just because they were in the turbo cars and 442's. I got lucky and found mine for 200 at a local swap meet and the guy just wanted his money back (wouldn't fit in his 59' el camino). A lot of times finding parts is either a stroke of luck, or it really depends on who you know. If you've got contacts, building a car can be a lot cheaper.
As far as rearends, I love the 7.5 and the 7.625 I have now out of a 86' monte ss, 3.73 gears. I had that rear end rebuilt with new yukon ring and pinion for about 300-400$. Now if you have a really serious setup, then yes a 9inch or 12 bolt will be best. I think the 8.5 is just a happy median and people are charging stupid money for them just because they were in the turbo cars and 442's. I got lucky and found mine for 200 at a local swap meet and the guy just wanted his money back (wouldn't fit in his 59' el camino). A lot of times finding parts is either a stroke of luck, or it really depends on who you know. If you've got contacts, building a car can be a lot cheaper.
slick843 said:
There are companies out there that offer direct bolt in 9" housing and axle packages for g-body cars (quick performance, currie, strange, moser, etc), or if you are a good with fab work, you can weld your own together...
I have been using the vortec heads for years. You can now get the from Scoggin Dickey with the springs for the highler lift cams already on them for around $600 or $650 for the pair. Go to their website for exact pricing. I went through 2 7.5 inch rears as well before going with the 8.5 from a g-body 442 or grand national. They are direct bolt in and are pretty strong stock.
Ive been looking into the 882 heads as an alternative. Im not building a drag car so I dont want to spend $1000-2000 on a set of heads. My goal is to get 300-350 hp out of my motor. I found some good priced remanufactured 882 heads on ebay but I read that the 882 heads are prone to cracking.
Think of the heads as an investment instead of just another part. You buy stock heads and you'll never make good power. An engine, whether it be a stock shortblock or full forged assembly relies on 2 things, getting air in and back out. The heads, cam, and intake are the *in* part of the equation. The best cam and intake will never do any good until you get a set of heads that will flow. I didn't learn this myself until I got a good set of heads and it was amazing what a differance they make.
You can buy some used heads that someone you don't know on ebay says are good (and hope they are) or you can spend a few dollars more and get brand new vortec heads that will out flow the 882's anyway.
You can buy some used heads that someone you don't know on ebay says are good (and hope they are) or you can spend a few dollars more and get brand new vortec heads that will out flow the 882's anyway.
as for a rear end i'll go wit a posi 373 grs...7.5 is okay..but like someone else said 8.5 is better...the ford nine inch if i'm not mistakin does take some fab....an as for the heads i'm still takin notes....but u can also do 3.42 gears...but i wouldnt go any higher than 4.10...
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