[m4erp]

Hi just got done talking to my machine shop guy ,He said he had to bore my 72 455 block 60 over to clean up the cylinders my Q: will this cause me any overheating problems ?
Also the engine has a set of 7M5 heads that the shop is redoing for this engine we talked about installing screw-in rocker studs and new valve seats are there any other mods that I should consider while these are being worked on? The car the engine is going into is a 1979 Transam with A/C a 350 trans and 2:73 gears Im also wondering what cam to install in this engine and intake ,Thinking of a Edelbrock preformer?
Give me some feedback please
Russ

[lust4speed]

I would have the cylinder walls sonic tested before putting the money in boring the engine. I had one that would have had a wall thickness of .028" if we had done the .060" bore. Wall thickness will depend on amount of core shift, and some blocks can take the .060" over bore without a problem.

[bnorris_74]

I vote stock 72 CI intake if you have it.
7M5 heads have an estimated 114CC chambers and no end holes for headers. Going .060 over is going to give your CR a bump but I don't know if it will be enough to make you happy.

I don't have a cam recommendation.

What are your performance goals?

[66bonne]

My 73 455 in my Catalina is 60 over - no overheating problems at all [plus the block is bottom filled].
The E-brock Performer will not give you any performance improvement; stock intakes are just as good. The E-brock Performer RPM is a good street strip intake.
Good luck and have fun,
Jim

[TIN TIGR]

i think he means the edelbrock cam..which is about like the baby summit cam, only costs more money..poo-poo

if ya have the money, check the block..map every cylinder if you can..then you know when ya bore..if your machine shop has a tester and your pals , check it after boring..just for fun and records..

dump the 7m5 heads..find some 350 heads, which have smaller chambers, or 400 heads..go for the 9.5 -1 cr..then pick the next cam up for a 455..they eat camshfts up..if ya think a stock cam will be ok, go one step up..example, 068 grind to ram air 3..

never bother with screw in studs if ya aint got much cammy or springs..and most good usable heads have screw in studs already..

[m4erp]

My Goal ,Well the car had a 301 ci from factory so Im hoping to at least double the horsepower of that engine somewhere in the 300 and up range.
Im not going to race this car just want to have some power when you hit the pedal.
I do still have the stock intake, and the block has already been bored to 60 over.
and heads are already in the process so that is what I have to work with now.
Thanks for you input bnorris74 Russ.

[m4erp]

Hi Tin Tigr block is already done 60 over and heads are almost done I did catch the machine shop and he said he will skip the screw in rocker studs and he also feels the engine will only have 8.5-1 cr so he doesn't think I need a big cam , and feels engine will develope 300 hp. So I need a cam that will work well with the 7M5 heads for now.
What do you feel duration /and lift will work best and is there a cam that will work for now but if $ and need arise I could replace heads later and not need to change the cam Thanks Russ

[m4erp]

Hi what is this bottom filling of block? and is it ok for the street use.You have no overheating problems what cam and heads are on your 455? 66 bonne Russ

[m4erp]

Ha lust4speed boring is done so Im hoping my 455 is one of the formentioned that can handle the 60 overbore. the shop doesnot have a sonic tester
Thanks Russ

[bnorris_74]

Originally Posted by m4erp

Hi what is this bottom filling of block? and is it ok for the street use.You have no overheating problems what cam and heads are on your 455? 66 bonne Russ

http://store02.prostores.com/servlet...gine%2C/Detail

P-Dude's store sells the stuff to fill the block.
He can clue you in on whether you need it for your application. Lot's of people use it on street driven engines.

Horsepower won't be as significant of a change as torque will be when you compare 301 vs 455 power.

["QUICK-SILVER"]

The '71' 66 head 455 had the same CR as the '72' 7M5 headed 455. 71 was rated at 325 HP and 72 was 250. This was the time when true HP numbers was messed with to make certain people happy.
That said; with your gears and driving plans, stock intake or port mated performer, 068 cam, and factory exhaust manifolds, should make one fine pump gas friendly torque monster. You'll easily more than double horse power but the torque factor is what will really blow your mind.

[m4erp]

Ha Quick-Silver thanks for the reply sounds like Im on the right track with this build ,for now I am thinking of useing the stock exhaust manifolds and a pypes performance exhaust system
Thanks Russ

[66bonne]

Block bottom fill is somewhat a kin to putting a girdle around the cylinders so that there is less flexing. Good insurance if you like to race a lot as we do with a block that is .060
over. Not necessary for street applications. Just pointing out that it does not create overheating situations.

Jim

[m4erp]

Originally Posted by "QUICK-SILVER"

The '71' 66 head 455 had the same CR as the '72' 7M5 headed 455. 71 was rated at 325 HP and 72 was 250. This was the time when true HP numbers was messed with to make certain people happy.
That said; with your gears and driving plans, stock intake or port mated performer, 068 cam, and factory exhaust manifolds, should make one fine pump gas friendly torque monster. You'll easily more than double horse power but the torque factor is what will really blow your mind.

Ha Quik-Silver what is the 068 cam you refer too? is it a pontiac cam and if so what is its duration and lift? IS THERE A AFTER MARKET EQUAL TO THIS 068 CAM?
Thanks Russ

["QUICK-SILVER"]

068 or 'S' cam was OE in the higher output 455's we're talking about. Don't have exact spec numbers for it but a search here should turn them up. I would imagine about every after market cam company has a replica or close replica of it.
It's a very user friendly super torquey off idle cam in a 455, and has plenty of mid range pulling power that'll go good with your tall geared rear end. It'll be a daily driver, smooth idler, grocery getter, that'll smoke the tires when you want it.

[Formulas]

If your sticking with the 7M5 heads then i would certainly convert to screw in studs..

Pressed in studs WILL pull out .. got to ask yourself ..why did the factory pretty much do it on every head that wasnt a 2bbl head???
Every factory engine that had a hint of performance had screw ins..

And i would slot the push rods holes in the heads along with a generous mill on them not forgetting to mill the intake side as well for anything over .020 dimension

[grivera]

Originally Posted by m4erp

Ha Quik-Silver what is the 068 cam you refer too? is it a pontiac cam and if so what is its duration and lift? IS THERE A AFTER MARKET EQUAL TO THIS 068 CAM?
Thanks Russ

Here it is:

http://www.summitracing.com/parts/MEL-SPC-7/

[m4erp]

Originally Posted by grivera

Here it is:

http://www.summitracing.com/parts/MEL-SPC-7/

thanks for the info Grivera I'll pass it on to my engine shop. Russ

[m4erp]

Originally Posted by Formulas

If your sticking with the 7M5 heads then i would certainly convert to screw in studs..

Pressed in studs WILL pull out .. got to ask yourself ..why did the factory pretty much do it on every head that wasnt a 2bbl head???
Every factory engine that had a hint of performance had screw ins..

And i would slot the push rods holes in the heads along with a generous mill on them not forgetting to mill the intake side as well for anything over .020 dimension

Thanks Formulas I,ll talk to my engine shop guy Russ