[Skip Fix]

Thanks for all the input. Going to throw a 455 together form parts I've got collected for years and try the M/T cross ram I got from Tom V years ago. Maybe even the Warrior TR on it too!

[72projectbird]

Had a pretty mild 455 filled to the bottom of the freeze plugs, and was totally fine.

If I didn't tell you it was filled, there would be no way you'd know.

[77 TRASHCAN]

Originally Posted by Skip Fix

Thanks for all the input. Going to throw a 455 together form parts I've got collected for years and try the M/T cross ram I got from Tom V years ago. Maybe even the Warrior TR on it too!

Which car?

[Skip Fix]

65 GTO. This block has 4 bolt caps added. I have a Ohio forged crank some Crower rods with a mini Dome Ross pistons to use with the 105cc 6X heads I got that are ported pretty decent. Figure that will get me a pump gas CR.

[ta man]

I have few years on my shortblock..water temps shouldn't be an issue. As far as oil temps..a temp gauge is a must..mine will climb after a spirited high speed run and if just driving slow in town.I've never gone over 250 degrees yet.normally I see 210 degrees. I'd suggest a oil cooler for sustained higher rpm runs.. I drove it roundtrip on the hottest day in our summer a few years ago just to test it. No issues. I think it was close to 100 degrees that day.

[Brian Baker]

I did it 20 years ago in my '79 T/A with a 455. Block was filled high too, to about 1/2" below the water pump holes in the front of the block. I drove it daily to work in all weather conditions for 19 months, from 90+ degree mid-Atlantic heat and humidity to light snow. Never had any issues with it. I ran the biggest 4-core radiator that would fit and a remote oil filter with a large capacity filter (system held 7 quarts with a factory pan and remote filter). I always ran 10w40 too, but don't know if that made any difference. Never had a gauge on the oil temperature but the coolant would typically run around 185 with normal driving, only getting up to near 200 on blistering summer days. My commute to work was only about 20 miles round trip, but did involve freeway speeds. With 3.23 gears I could still cruise at 70 MPH comfortably.

[steve25]

Hey Skip, before you try out the MT crossram try to talk to someone who had run one, especially if it will have to run street miles.

I had a uncle’s friend back in the early 80s who was trying to run one he slapped onto his 421 2+2 Cat and could never get it to run all that great below some 4000 rpm, and this was with running two Cater AFB carbs with progressive linkage that each where tested as running fine on a 389 motor.

You would have thought that with those wonderful long runners that it would have had the best of both worlds so to speak!

I recall the issue turned out to be that the intake has no balance tube section or some such between its passenger and drivers side carb Plenum supposedly?

[PontiacJim1959]

Originally Posted by steve25

Hey Skip, before you try out the MT crossram try to talk to someone who had run one, especially if it will have to run street miles.

I had a uncle’s friend back in the early 80s who was trying to run one he slapped onto his 421 2+2 Cat and could never get it to run all that great below some 4000 rpm, and this was with running two Cater AFB carbs with progressive linkage that each where tested as running fine on a 389 motor.

You would have thought that with those wonderful long runners that it would have had the best of both worlds so to speak!

I recall the issue turned out to be that the intake has no balance tube section or some such between its passenger and drivers side carb Plenum supposedly?

Progressive linkage won't work as one carb feeds the left cylinder bank ad one carb feeds the right cylinder bank - no balance tube. This is why they are a racing intake and not so much street friendly, BUT, look cool. For 5K, you can buy this NOS one on Ebay.

[steve25]

Jim you are correct concidering what I posted.
What the detail I left out was he used a progressive linkage that he locked out to be 1 to 1 as was needed.

Also Skip you need a timing cover that will accept a tripower intake unless you mill off that whole front water crossover section and cobble some tube deal up with a separate bubble section to house the Tsat.

How do those monsters weigh in at?

[Tom Vaught]

Skip can probably post up a picture of the intake I had modded for Him, one for myself, and one for the welder (a Pontiac Guy). This was done at least 10 years ago if not longer.

In each case a Balance Tube connects the two plenums. The balance tube is a 1" diameter piece and connects both plenums across a 4 inch space in the center of the two plenums. The original front water crossover was modded for 65 up heads and the ports were lowered for the 65 intake placement and will use a tiller port gasket. Nothing was "cut off".

I sold a unmodded crossram to a PY guy from Missouri last year and so now I just have my Modded one.

I had those mods done for a reason. Street use.

Tom V.

[Skip Fix]

Steve I think the tube Tom had added will help. Not looking of optimal performance as on the flow bench I think my T2 flowed better. But it will going to use the two Holley 715s I ran on my 409 back in the 70s. Had them freshened and a PV front metering block since they originally had no PV in them. On the 409 they had to have the vacuum dashpot taken off to fit sideways and "pinned" so all 8 barrels opened at once. But then gas was 0.30/gal back then!

[Skip Fix]

I have an aluminum Tri Power water neck I'm going t grind to fit the timing cover with some weld on thwe inside to make it thicker there.

[Brian Baker]

Chuck Roberts did some extensive testing with the M.T. Cross Ram back in the early-mid 80's in his 4-speed '65 GTO powered by a R.A. IV head 428. Long story short, it was a dog at anything below 4500 rpm, but above that it would rip your head off. Consequently, this adversely affected 1/4 mile times when compared to a Tri-Power or a Q-Jet (which was also tested). And yes, they cut up an original M.T. intake to fit the later heads.

[77 TRASHCAN]

Hot Rod magazine tested a bunch of intakes, years ago, of course on a small block Chevy. It was a good read. They tested a cross ram, and it had reversion issues, didn't do that well on their dyno. I obviously don't remember many details, BUT, was wondering if joining carb spacers with some sort of connection, could be made to possibly help remedy??? Tom V.?

[Tom Vaught]

IF the crossram (assume it was a M/T Pontiac Intake) a balance tube would help a lot for sure. Just like the larger Rectangle balance passage between the two plenums on the Nash T/R Intake. The Offy Dual Quad had the same issues BUT the runners are much shorter

Tom V.

[Formulas]

A very prominent highly regarded member of the Pontiac community told me one time that he had a Pontiac M/T intake engine on a dyno one time and the reversion was so bad that there was a plume of gas vapor being kicked up out of the carbs a substantial distance

As always the devil is in the details but it may take alot of wrangling of cam events and exhaust tuning to reduce this tendency

Strange that Plymouth got their super stock stuff to work decently, or maybe they didn't

.

[PontiacJim1959]

Here is a pic of the factory offered Mopar cross ram, they had 2 different lengths. I believe the long tube was early and was determined to be too long, so they came out with the second design shorter ram tubes.

You can see how they joined the 2 plenums - each one has a tube that was joined together, I believe with a hose, to create a balance tube.

I should have bought the set I saw at a swap meet for $100 in the early 80's, but I was not a Mopar guy.

[taff2]

Those 90 degree bends right out of the plenums can't be good for flow on the M/T, look how the Mopar cross ram has almost straight runners out of the plenums.

[blueghoast]

I put carb spacer's on mine but haven't tryed it yet

[krisr]

I half filled my 400 with "Hardblock" and straight away noticed oil temps increased around 20*C, on the highway even higher. I ended up putting an oil thermostat and an oil cooler on the car and now my oil temps operate at the thermostat rating in any ambient temperature. Best of both worlds.