|01-02-2013 04:30 PM|
12-600-4 - Thumpr
Thumpr cams have gotten a bad rap from a lot of fellows, but they work fine if you're more interested in lope than total performance.
|01-02-2013 11:30 AM|
|454C10||I have tapped double humps and the holes go all the way through the head and into the valve cover area so you must use RTV on t threads. On a mild street engine regular seats are OK.|
|01-02-2013 10:46 AM|
|01-02-2013 10:20 AM|
I do not think installing hardened seats in early heads was that big a deal if you need to do the heads anyway,,
|01-02-2013 10:19 AM|
Oh ok most have had the seats changed out by now. But yeah if the seats are still from 1960 then you will need to change them out as well. I bet you could get a few bucks for them on ebay since they are unmolested for 40 years. Usally they had the seats done in the 70's.
You can drill and tap the same holes as any chevy head. Most of the bolt is in the boss anyway. Really does not need to go very deep.
Most cars of that time did not have a/c in performance cars so the heads were not drilled unless you had one with the options for a/c and engine that came with humps OEM.
You can also always run the alt and power steering down low in the old school position.
hope this helps some.
|01-02-2013 10:07 AM|
|01-02-2013 10:04 AM|
Why not just have the holes drilled in the heads you have. It does not cost much and is even easy to do at home.
Humps will work just find in this case.
|01-02-2013 09:52 AM|
If you just want a budget street oriented build use the short block and heads you have, pick up a 268h cam, a set of headers, an HEI ignition, and dual welded thrush mufflers. It'll have a moderate "hotrod" sound but be very street friendly, durable, and easy to build.
Since its street use the only other thing I may consider is converting to EFI, even throttle body injection will be an improvement over most carbs.
That combo is nothing new or hightech, but its reliable and cheap. The mufflers will give you the sound you're looking for, you may need to adjust the idle down to about 600rpm though.
|01-02-2013 09:38 AM|
|vinniekq2||double hump heads are fine.|
|01-02-2013 09:26 AM|
Yes we will be putting headers on. And valve size, 194, sorry for the confusion not runner size. This is strctly street, no drags or hotrodding. Kids first car, he wants it to sound mean! Budget build!!
I have a set of double humps, will check casting number
|01-02-2013 04:58 AM|
What kind of flat tops? send a photo or part number.
What is the deck height? The amount the piston is below the deck at tdc. (Typically 0.020" but and range between 0.000 and 0.030")
Stock gm sb heads are typically between 150cc-160cc. So you will need an aftermarket head to get 195cc.
Early sbc heads are typically 64cc chambers. What casing numbers on your heads?
195cc head on a 350 is not a setup for low rpm torque. Better off with 160cc ports.
Plan on using headers for max torque.
|01-01-2013 11:11 PM|
What heads to use
You will want to find a 76cc chambered head made after 1973 so it will have hardened seats. The 195 is that intake valve size or intake runner size? Here is a list of 76cc chamber, 1.94 intake valve heads. Last 3 digits, 997,993,882,487, 493,598, and 441.
|01-01-2013 10:57 PM|
Early pre 1969 heads are fine with aftermarket accessory mounting brackets.
Chevrolet Steel Mounting Brackets
What casting do you got? they are not all the same and not all desirable.
|01-01-2013 10:52 PM|
|01-01-2013 07:09 PM|
|vinniekq2||what heads are in your possession?|
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