Apr 03, 2022
I will try and be as detailed as possible.
-I have a 78 Bronco, 351 gears 35 inch tires
--I swapped in a Ford 300 I6 and a T-18 Tranny/Tcase from a 1980-81 ish Bronco.
---It has a single barrel carb, stock intake/exhaust
---Here is the issues, I have great low end torque, slow to moderate acceleration. When I shift from 2nd to 3rd, all is good. When I shift from 3rd to 4th,( RPMs around 2200-2500) my RPMs will drop around 1000-1200, and it will take FOREVER to gain speed. If I am going up a hill it will drop to 45 MPH and creep forever untill it can gain momentum and speed up. Once my MECHANICAL advance kicks in around 1600-ish, then I can gain speed again.
-----Things I have tried
-I installed a vacuume guage, no matter if I connect it to carb vac or man vac, it DOES NOT MAKE A DIFFERENCE. This may or may not be an issue. It changes wheather I have vaccume at idle, but once I am driving, if I shift and get back on it, the vaccume goes to zero.....
-I have advanced my distributor to max advance (total advance) and it RUNS GREAT!!!!! However, once I shut the truck off it will not start. I have it set now where cold start and hot start are both pretty easy.
---I have put a new distributor on
---I have changed the mechanical springs-set my advance stops
---all back to stock distributor now
Nothing fixed it. is there a distributor I can get that will be tunable for cold/hot starts, but kick mech advance in at 1200? is the vac advance ports faulty?
I realize 351 gears were not stock for a I6, and 78 is a bit heavier, but still.......
-I have a 78 Bronco, 351 gears 35 inch tires
--I swapped in a Ford 300 I6 and a T-18 Tranny/Tcase from a 1980-81 ish Bronco.
---It has a single barrel carb, stock intake/exhaust
---Here is the issues, I have great low end torque, slow to moderate acceleration. When I shift from 2nd to 3rd, all is good. When I shift from 3rd to 4th,( RPMs around 2200-2500) my RPMs will drop around 1000-1200, and it will take FOREVER to gain speed. If I am going up a hill it will drop to 45 MPH and creep forever untill it can gain momentum and speed up. Once my MECHANICAL advance kicks in around 1600-ish, then I can gain speed again.
-----Things I have tried
-I installed a vacuume guage, no matter if I connect it to carb vac or man vac, it DOES NOT MAKE A DIFFERENCE. This may or may not be an issue. It changes wheather I have vaccume at idle, but once I am driving, if I shift and get back on it, the vaccume goes to zero.....
-I have advanced my distributor to max advance (total advance) and it RUNS GREAT!!!!! However, once I shut the truck off it will not start. I have it set now where cold start and hot start are both pretty easy.
---I have put a new distributor on
---I have changed the mechanical springs-set my advance stops
---all back to stock distributor now
Nothing fixed it. is there a distributor I can get that will be tunable for cold/hot starts, but kick mech advance in at 1200? is the vac advance ports faulty?
I realize 351 gears were not stock for a I6, and 78 is a bit heavier, but still.......
Last edited by a moderator:
Apr 03, 2022