I think there are better places to spend ones money first. The roller
rockers are not as trouble free as the original rockers which are very easy
and cheap to replace (about $32 for both heads).
Heres what I intend to do and will not be surprised at 11-12 MPG, just my
ideas, but someone else had asked me what I planned to do:
1. Replace the J heads on the 1976 with E heads with stainless steel
valves, new bronze valve guides, Martite Mondello valve seats(part # 1423,
$56), filled exhaust cross overs, teflon seals. The big valve heads really
let the 455 breathe. The J heads were the worse heads made for the 455.
2. Thorley headers with Swain ceramic coating inside and out (I have
already had that done but not installed them yet). Increases the thermal
efficiency of the engine and dramatically cuts down underhood heat.
3. New Motorhome camshaft (JM-15-100, $129)from Mondello.REally increases
low end torque and HP where we need it.
4. New camshaft button to restrict the camshaft movement and give more
consistent timing. When you remove the front timing cover you should check
for severely pitted metal in the cover which is prevelent in most 455 blocks
and replace it if needed with a Mondello TC525, $42 for the 455.
5. Remanufactured HEI distributer, blueprinted, curved for the GMC
motorhome etc, from (Dick Paterson, springfield Ignition) approx $180.00
6. New Mondello 7150 ($329) heavy duty furnace brazed Torrington roller
bearing torque converter with a stall speed of 1800-2000RPM, designed for
the GMC motorhome. This unit is the toughest unit that you can buy for
towing or heavy duty service for the GMC motorhome. I am going to use
synthetic tranny fluid in it.
7. Perma-cool, PRM-12311 HD transmission cooler with 500CFM fan and
thermostat, $131.95 from summit.Add a remote oil cooler thermostat to by
pass the oil below 180 degrees for faster warm up. part # PRM-1060, $34.95
available from Summit. Remove lines from tranny to radiator.
This modification will also improve the engine cooling in HD towing.
8. Perma-cool transmission oil filter with temp gauge PRM-10677 $78.95.
9. Cloyes double roller timing chain and gears, available from Mondello
(TR-252, $89) or summit (CLO-9-3113, $78.95). If your engine has many miles
on it this is needed and really a big improvement in timing accuracy. You
really should properly degree your cam when replacing the chain and cam.
10. rebuild the carb with new jets for todays poor gas. this alone should
increase your gas mileage and performance.
For those of you that are still looking for vacuum pumps for auxiliary
brakes when your engine stalls, Mondello has them. part # 3723, a self
contained vacuum pump, comes on at 21" of vacuum and off at 21". Price $269.
with ( first on my list is a hot distributer and MSD module. At 05:27 PM
>
>
>Met a guy in Seattle who had installed roller rockers on his 455. This is
>just one in a long list of things he had done to get his gas mileage up to
>10.5 MPG. Now I want to tell you there hasta be a lot of flat ground for me
>to even get close to ten MPG. And the fuel injection and headers are at the
>very top of MY list. But!! Old age has taught me that it's the little things
>that make the difference. What do you think?? is it worth considering?? Or
>is this that gray area that just makes you feel good to spend the money.
>
>Terry & Diane Skinner
>Webfooted in Washington
>'76 Glenbrook
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
rockers are not as trouble free as the original rockers which are very easy
and cheap to replace (about $32 for both heads).
Heres what I intend to do and will not be surprised at 11-12 MPG, just my
ideas, but someone else had asked me what I planned to do:
1. Replace the J heads on the 1976 with E heads with stainless steel
valves, new bronze valve guides, Martite Mondello valve seats(part # 1423,
$56), filled exhaust cross overs, teflon seals. The big valve heads really
let the 455 breathe. The J heads were the worse heads made for the 455.
2. Thorley headers with Swain ceramic coating inside and out (I have
already had that done but not installed them yet). Increases the thermal
efficiency of the engine and dramatically cuts down underhood heat.
3. New Motorhome camshaft (JM-15-100, $129)from Mondello.REally increases
low end torque and HP where we need it.
4. New camshaft button to restrict the camshaft movement and give more
consistent timing. When you remove the front timing cover you should check
for severely pitted metal in the cover which is prevelent in most 455 blocks
and replace it if needed with a Mondello TC525, $42 for the 455.
5. Remanufactured HEI distributer, blueprinted, curved for the GMC
motorhome etc, from (Dick Paterson, springfield Ignition) approx $180.00
6. New Mondello 7150 ($329) heavy duty furnace brazed Torrington roller
bearing torque converter with a stall speed of 1800-2000RPM, designed for
the GMC motorhome. This unit is the toughest unit that you can buy for
towing or heavy duty service for the GMC motorhome. I am going to use
synthetic tranny fluid in it.
7. Perma-cool, PRM-12311 HD transmission cooler with 500CFM fan and
thermostat, $131.95 from summit.Add a remote oil cooler thermostat to by
pass the oil below 180 degrees for faster warm up. part # PRM-1060, $34.95
available from Summit. Remove lines from tranny to radiator.
This modification will also improve the engine cooling in HD towing.
8. Perma-cool transmission oil filter with temp gauge PRM-10677 $78.95.
9. Cloyes double roller timing chain and gears, available from Mondello
(TR-252, $89) or summit (CLO-9-3113, $78.95). If your engine has many miles
on it this is needed and really a big improvement in timing accuracy. You
really should properly degree your cam when replacing the chain and cam.
10. rebuild the carb with new jets for todays poor gas. this alone should
increase your gas mileage and performance.
For those of you that are still looking for vacuum pumps for auxiliary
brakes when your engine stalls, Mondello has them. part # 3723, a self
contained vacuum pump, comes on at 21" of vacuum and off at 21". Price $269.
with ( first on my list is a hot distributer and MSD module. At 05:27 PM
>
>
>Met a guy in Seattle who had installed roller rockers on his 455. This is
>just one in a long list of things he had done to get his gas mileage up to
>10.5 MPG. Now I want to tell you there hasta be a lot of flat ground for me
>to even get close to ten MPG. And the fuel injection and headers are at the
>very top of MY list. But!! Old age has taught me that it's the little things
>that make the difference. What do you think?? is it worth considering?? Or
>is this that gray area that just makes you feel good to spend the money.
>
>Terry & Diane Skinner
>Webfooted in Washington
>'76 Glenbrook
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
