75 360la specs?

[bigfury3]

Hey guys I recently pulled a running 360la out of a motorhome has 50,000 miles on it. So my plan is to do a mild rebuild on it to swap into my 66 fury III daily driver I plan on later doing full rebuild around a year from now once I stock pile some parts. Ok so I've been looking online trying to find the engine specs(horsepower/torque) but can't find any info. It has a Edelbrock performer intake and 4bbl Carter AFB carb on it, I pulled it out of a 76 tradesman but the block casting year says 75 any info you guys can provide will be appreciated.

 

[CBODY67]

Block casting dates can pre-date the model year of the vehicle, if the vehicle was an early-in-the-model year produced vehicle.

In your case, the actual specs of the motor would be for a 3/4 or 1-ton van chassis of that model year. Probably the same specs as a D200 pickup, I suspect. Which also probably means the same cam and CR as the low compression car engines of the time.

In the Chrysler world, "Motorhome" means something from the days of Travco and similar motorhome chassis vehicles, which then relates to some more-HD than normal 440s. BTAIM

The vehicle probably had the "car" style ThermoQuad 4bbl and the matching cast iron intake manifold. The current manifold and carb you mention are probably there for a reason OTHER than better power production. End result is that power should be the same as the as-produced motor, most likely.

It is very possible that you will need some 1967 LA mounts for your car? As Chrysler changed styles in about 1972 or so, so your van-chassis mounts are most probably the later style.

Aim for something in the spec range of the 360HP cam. The current carb and intake manifold will be fine. Hopefully you got the electronic ignition items from the donor vehicle?

Just some thoughts,
CBODY67

 

[bigfury3]

Block casting dates can pre-date the model year of the vehicle, if the vehicle was an early-in-the-model year produced vehicle.

In your case, the actual specs of the motor would be for a 3/4 or 1-ton van chassis of that model year. Probably the same specs as a D200 pickup, I suspect. Which also probably means the same cam and CR as the low compression car engines of the time.

In the Chrysler world, "Motorhome" means something from the days of Travco and similar motorhome chassis vehicles, which then relates to some more-HD than normal 440s. BTAIM

The vehicle probably had the "car" style ThermoQuad 4bbl and the matching cast iron intake manifold. The current manifold and carb you mention are probably there for a reason OTHER than better power production. End result is that power should be the same as the as-produced motor, most likely.

It is very possible that you will need some 1967 LA mounts for your car? As Chrysler changed styles in about 1972 or so, so your van-chassis mounts are most probably the later style.

Aim for something in the spec range of the 360HP cam. The current carb and intake manifold will be fine. Hopefully you got the electronic ignition items from the donor vehicle?

Just some thoughts,
CBODY67

I pulled the wiring harness and everything it was hooked to it as the guy was going to scrap the motorhome. I've read online that I can use the engine mounts for the 318 poly In my car just have to use washer and spacers to compensate for the difference. When the time comes hopefully that is so because I don't really want to buy a set from schumacher. I already bought a centersump oil pan kit from mancini racing. Ok so from what you've said the horsepower is probably like 240? I'm just trying to figure out if I should go through with a stroker kit when I do full rebuild cause I'm aiming for around 350 to 400 HP build.

 

[Knebel]

I have a 76 360. It also has an edelbrock intake and an unspecified cam. Looking at my injector flowrate and the formular for HP mine probably makes betwee 350 and 400hp somwhere. Definately has more power than my 280hp jeep.

 

[bigfury3]

I have a 76 360. It also has an edelbrock intake and an unspecified cam. Looking at my injector flowrate and the formular for HP mine probably makes betwee 350 and 400hp somwhere. Definately has more power than my 280hp jeep.

Really do you have the stock heads on or aftermarket?

 

[Vaanth]

The engine shown with a 12-17-75 block casting date is a 1976 model year engine. Within the motor home and other chassis builder industries, the finished product model year can be even later, but the Chrysler assigned model year for the engine should be 1976. The sticker on the valve cover, if original and still legible, should provide some additional detail for tune up settings, emissions, etc.

The engine build information is on the front left of the block right below the cylinder head. It will be similar to the following example:

6M 360 5270 1234

Where:
- 6 is the model year, 1976
- M is the build plant, Mound Road
- 360 is the engine size
- 5270 is the build date, in this case January 1, 1976
- 1234 is the sequence number for the engines built that day.

1975 and 1976 truck/van/chassis 360 engines were available in two versions, 360-1 (light duty), 360-3 (heavy duty). Both 360s were only available with two barrel carburetors originally. Holley model 2210 was used on 360-1 Federal and Canada applications. Holley 2245 was used on California 360-1 and all 360-3 applications.

General specifications for these 360 engines include the following:

Horsepower = 175 (net) @4000RPM
Torque = 285 (net) @2400RPM

Compression ratio: 8.4:1 (360-1), 7.9:1 (360-3)
Hydraulic tappets
Camshaft intake valve lift: 0.410", Duration: 252
Camshaft exhaust valve lift: 0.400" . Duration: 256
Head castings: 4006337 or 3769974
Intake valve size: 1.88"
Exhaust valve size: 1.60" (exhaust valves have rotators)
Timing gear/chain: 360-1 is nylon/single, 360-3 is double roller

These specifications are for the original equipment.

 

[CBODY67]

How was the horsepower target arrived at? Just curious.

There is a segment on Nick's Garage YT channel where he dynos a 408LA motor, out of a customer's 'Cuda, with an undisclosed cam, that made 425 horsepower. Not sure how that happened!

CBODY67

 

[bigfury3]

How was the horsepower target arrived at? Just curious.

There is a segment on Nick's Garage YT channel where he dynos a 408LA motor, out of a customer's 'Cuda, with an undisclosed cam, that made 425 horsepower. Not sure how that happened!

CBODY67

For the most part I've just been going off of this article Modifying And Testing A Dodge 360-Cube LA Small-Block On The Dyno

But I only know what I know just trying to get some feedback from the guys on here there's always something to learn and I'm just trying to figure out what I have

 

[CBODY67]

For the most part I've just been going off of this article Modifying And Testing A Dodge 360-Cube LA Small-Block On The Dyno

But I only know what I know just trying to get some feedback from the guys on here there's always something to learn and I'm just trying to figure out what I have

That is an interesting build. Reason is that it is more "normal" oriented than numbers-oriented. Where "big numbers" as sought rather than something for everyday use.

In looking at cams, seek lobe configurations which are asymmetrical, which CompCams introduced in the 1980s in their old "High Energy" series of cams. Where they opened the valve fast, held it, and then closed it slower. More area under the lift curve. I bought one of the HE268s for a 440 I was thinking of building. I chucked it up on the block with a Mr. Gasket degree wheel on the crankshaft nose. Set up the magnetic dial indicator to check true TDC and then to measure lobe lift at the end of a pushrod. The numbers on the cam card were accurate, but what I was not prepared for was that max valve lift was maintained for a full 10 degrees of crank rotation.

I also put in a genuine Mopar Perf Direct Connection Street HEMI grind Purple Shaft cam (ordered from Gratiot Auto Supply, with a set of lifters to match), rather than what they have been calling "Purple Shaft" for a few years now. It, probably like every other OEM cam, was at max valve lift for only 1 degree of crankshaft rotation. I did these things in the 1990s.

In more recent times, Lunati also claims to have some similar-lobe cams, too. So look at the literature. Heading toward 112 degrees LCA can help idle vac a bit, over the 110 LCA, but have no real impact on 3K+ rpm power, from the dyno runs on LCA I've found online.

From the looks of those power levels, might not need a stroker!

Take care,
CBODY67

 

[Knebel]

Really do you have the stock heads on or aftermarket?

They look like stock heads but I have no idea if anything was done to them. This motor is a mystery machine as the guy I bought the car from did not have a clue what was previously done to it other than "souped up" "has a cam in it". I can just go by "feel" and did some reading on fuel flow and corresponding HP and such. I also know that I barely ever even arrive at 50% throttle haha

Edit: the formular for lb/h of fuel is: HP x0.5=lb/h. Alternatively you can use lb/h÷0.5=hp.

I flow between 190 and 206lb/h at 5500rpm.