Join Date: Jul 2014
Location: Space Coast Florida
Can anyone post a dyno sheet for a 400 or 408?
Last month when a main bearing started knocking over 3K rpm's, we pulled our 351M out of my son's 76 Ranchero and got it rebuilt and upgraded with a few choice items.
I know the stock 351M in our 76 Ranchero was a low-compression smog monster and did not make much power from the factory.
From Automobile Catalog: gasoline (petrol) engine with displacement: 5766 cm3 / 351.9 cui, advertised power: 115 kW / 154 hp / 156 PS ( SAE net ), torque: 388 Nm / 286 lb-ft
The compression was 8.2:1 for 74-76 car engines (it got worse and went down to 7.8:1 in 78-79 cars).
I guess the original 76 351M car engine was swapped out some time ago.
We found out our 76 Ranchero has a November 1977 casting date truck block D7TE, the reinforced, upgraded, good one.
The only numbers I could find for the 77 351 and 400 truck engines was on Bubba's M-Block site and don't include compression ratio or torque, just hp: 400: 173HP @3800 rpm 351M: 161HP @3400 rpm.
Also according to Bubba's M-Block site: 79 400 truck stock hp and torque: 159 HP @3800, and 276 torque @2000
We bored it, stroked it, and brought the compression way up, but have to use some stock stuff up top because of our budget.
What we did to our 77 351M truck engine:
351 crank and 351 deep dish pistons replaced with 400 crank and 400 shallow dish pistons to make it a 400. Then had block bored .030 to make it a 408. all new main, rod, and cam bearings.
Replaced retarded timing chain set with Edelbrock timing gears and chain, set to "straight up".
The timing set and piston change will take the compression back up to over 9.1:1, how much, I don't know.
Edelbrock 2172 RV/truck/towing cam, new edelbrock valve springs, retainers, keepers, and valve stem seals.
What we have to keep for now:
Factory 2150 2BBL carb, iron intake and exhaust manifolds.
I'd like to know what to expect from our fresh 408 in terms of HP and torque. I think it will be a beast in a 4300 lb. Ranchero, but some actual numbers would be cool.