I have decided that changing my 302 over to a 351W is going to be a bit more of a hassle than I want to undergo (and lots more expensive.) Thinking about upgrading the 302 now...

My plan includes switching it to mass air, but also adding the following (before the Kenne Bell supercharger goes on):

1. BBK twin 61mm high-flow throttle body
2. Bassani "shorty" header/high-flow catalytic converter system

These parts are for sale on Truckperformance.com. Question is, will the power and torque numbers they quote be additive? #1 should give 15hp and 20ft-lbs, #2 should give 44hp and 64ft-lbs. So does this necessarily mean that I'll come close to a net gain of 59hp and 84ft-lbs just by adding these parts?

Can anyone answer that question, or give me inputs into these or any other improvements to the 302?

Thanks,
Mike

 

hi mike,
I had a 90 lariet that was a real dog. after 12K-the warrenty ran out-I built a mid-range 302 w/comp cam-9.5 pistons-stock efi. After install , it was no better--maybe a little worse. Then I tried 3" exhauts & no change. Next an airbox mod. Nothing would make that truck run. I think ford's eec4 said that engine made xxx hp & no more. If I recall, the figure was 165 hp. hope you have better luck.

 

Thanks for your reply. Ford's stock computer has been a concern all along. If it really looks like it's going to present a problem, I'll have to reconsider going with the carbureted 351 swap and stop thinking about registering the truck in Texas (home) because it won't pass emissions laws...

 

Mike
Both of those performance increases are optimistic to say the least. Muscle Mustangs & Fast Fords installed the full Bassani system on a 1st gen Lightning and got something on the order of 20-25 rear wheel HP. Good improvement, but a long way from 44. The T/B should be worth like 5-10 rear wheel HP without other mods to support it. A lot of these manufacturers HP numbers come from a modified engine missing only their part necessary to make it work properly. When they bolt that part on they see huge gains because it enables the other stuff to work.

For example, if you take a moderately built GT-40 engine capable of putting out 300 HP and run it thru a stock exhaust, you'll only see 250, bolt on the Bassani and you've got a 44 HP gain. On a stock truck, you're probably seeing 155-160 at the rear wheels, bolt on the Bassani, you'll probably see 175 or so. Build the engine up to where it can use the additional breathing and you'll see more.

Other simple mods to consider: 1.7 rocker arms, a real 10 HP at the wheels with no loss of bottom end power; a phenolic spacer between the upper and lower manifolds, good for maybe 5 HP by cooling the intake charge: underdrive pulleys if you already have excess cooling capacity and especially if you're going to put in big gears, good for 7-10 HP.

If you want to get into the engine, then a cam and kit, iron GT-40 heads, extrude honing the intake, etc. all produce noticable gains.

 

Well, it is getting close to engine rebuild time. What is extrude honing and will it decrease engine reliability at all (I'd expect not)?

I suspect with a few mods this truck will perform acceptably.

Thanks,
Mike

 

basically they pump an abrasive slurry through the manifold and it polishes all the internal surfaces and removes a small amount of material, giving you better airflow. It can be done on any "dry" EFI manifold that is cast, but not on fabricated ones like the GT-40 upper