The 305 is a small black Chevy in the gmc truck. So yes it has a right and left bank = 2 heads one on the right and one on the left...
stand at the front of the engine. the cylinder head at your left is actually your right bank, and the head at your right is labled as your left bank, as if you were to label them in reference from the position of being seated in the truck. but for simplicity I will give you reference from the perspective of standing in front of the truck, facing the engine, because that is the way you will be working on it.On the left bank, or the cylinder head at your right, the cylinder closest to you is Number 1 Cylinder. The next one back on the same head is Cylinder Number 3. And the left bank Cylinder closest to the firewall, furthest from you, is Cylinder Number 5.Let's go to the right bank, or the cylinder head at your left standing in front of the motor. The Cylinder closest to you is #2, then #4, and the cylinder furthest from you on this head, closest to the firewall, is then #6.So, the most important aspect of the answer: the firing order is very simple! This is your firing order. 1-2-3-4-5-6
looking at the front of truck number 1 cylinder is on right handside right behind powersteering pump
When your sitting in the car facing forward your right and left arms are the same as the right and left side of the vehicle.
The master cylinder should be bench-bled prior to installation. Then, right rear, left rear, right front, left front.
On the right side or the left side of the head.
It is right on the top side of the firewall just to the left of the master cylinder
2,4,6 from left to right on front bank,1,3,5 from left to right on rear head.(when facing engine from front of van)
Right Front Cylinder.
Standing at the rad. Front head left to right, 2-4-6 Rear head 1-3-5
1-8-7-2-6-5-4-3 Cylinder numbers ( front to rear ) Left (driver's) side head...1-3-5-7 Right head Passenger side..2-4-6-8
It is on the right head, It's the first spark plug in the front of head. Firing order is 1-5-3-6-2-4 Right head front to rear is 1-3-5 Left head front to rear is 2-4-6 This is you standing in front of engine.
Standing at the radiator. Front head left to right, 2-4-6 Rear head 1-3-5