Thread: 69 390 build

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I'm an old Chevy guy but a friend of mine wants me to rebuild a 390 for him. He's looking for a street machine that will also be able to crusie 65 on Hwy. He likes low end torque, a bit of a lope at idel.
We paln on doing the standard machine shop stuff, valve job on the heads, shaved if nessasary, hot bath the block, check for deck straightness. bore/hatch as needed.
Budget is around $2,000.00
This is my first 390, I have gone through my own 302 twice, any big differences?
Other than a standard rebuild kit we are looking at a Comp 33-238-4 cam and a 700 cfm Edelbrock on a Performer PRM intake with headers.
What do you think?

Boy I sure need to check spelling before I push the button....
Wow, that's awful,,, Sorry

I am repling to you about the cam you want to use in your 390 build. I have a 79 ford 4x4 and it had a 400m in it but I did not like it so I rebuilt a 390 and put in it. I put a cam in it with to much lift and all I do now is bend push rods and a friend told me that on FE heads you must have the push rod ports inlarged to give them room for a higher lift cam.

Craig: I think you guys are gonna be dissapointed with that 700 carberator, escpecially if you've got the motor camed. You should probably go with at least a 750. Hate to see you be disapointed, I'm sure someone has a calculator that tells you what carb. you should be running. Then if you have the engine camed you should run a little more. I'm running a 750 on my 351 Cleaveland and so is a buddy of mine, and he just went to an 850, but he's turning about 8,000 R.P.M.'s. The factory was puting holley 780's on a lot of the performace 390's. Some even ran three two barrels and two 4 barrels 652 holleys.

Vegas

What is the big difference in the RPM vs the Performer?

For sure we will figure the compression before the cam choice, we were just plugging in some numbers in the Dyno 2000 program to see what we were working with.
If we need to deck the block or shave the stock heads we don't know the numbers yet. Pistons and a final bore dia. are needed.

Any help is greatly appeciated!

Craig; Once you have Picked the cam your going to run then choose the Intake manifold. You have to make sure that the RPM ranges all match for the best performance, then you have to make sure the bottom end is in line with the rpm's you want to turn. It doesn't make any sence to buy a 8000 rpm cam when the bottom end is going to come apart at 6000 rpm's Do you know what I mean. The performer is good from idle to 5500rpm's and the rpm performer is good from 1500rpm's to 6500rpm's So you guy's need to decide if he wants to use this truck for towing or racing. The cam you choose should be with in the rpm range of the intake you choose. And the bottom of that 390 will come apart after about 6000rpm's so your better off with the performer Intake. Unless you plan on sticking thousands of dollers in the bottom end of the motor and oiling system. Hope this helps you out.


Vegas

craig, to figure out you carb try this formula and if anyone doesn't believe the chick they should try it too! take you new CID x max rpm (estimated red line) and divide by 4567 that will give you the needed CFM of you carb

I was wrong one the botom number. I looked at the Holley web page. It is CID X max RPM divided by 3456 not 4567. Sorry for the miss info