I have a ’68 Barracuda with a 340 engine, and it is modified with the usual aftermarket goodies. The engine has no emissions equipment, and it runs just great. I want to further upgrade the engine, and I am now thinking about adding an aftermarket fuel injection system. I read about the FAST EZ-EFI, and it seems like a simple upgrade, with the injectors in the throttle body just replacing the current Holley carburetor, and the self-learning programming. I’m debating whether to go with this system, or just run a full EFI system with the injectors in the manifold. What are the pros and cons of the two types of systems?

Henry Watts

Henry, FAST can provide you with either type of system, and perhaps your best bet would be to discuss the virtues of each with the manufactures by calling them on their tech line, 877/334-8355. The throttle body will be less complex, easier to install, and more cost effective. A full multipoint injection system will offer more tune-ability and more precise metering, but is a more involved conversion.


I have a ’72 Demon, that has accumulated quite a few miles, and a buddy suggested flushing the engine with transmission fluid. He is experienced with working on engines, and said it would clean out all the sludge and muck in the engine, and make it clean as new.

We drained the crankcase, added four quarts of transmission fluid, a quart of motor flush from the parts store, and a pint of diesel fuel. We drove the car for about an hour until the oil was working well up to temperature, and everything seemed normal. We then went and drained the oil and it was plenty dirty! We decided to repeat the treatment, and did the process all over again. We drained the oil again, and then changed the filter and filled the engine with 5-15 synthetic. This oil was way more costly than regular oil, but my buddy told me that these modern oils are way better and would give the engine more power, make it wear less, and prevent sludge from coming back.

Now my problem is the engine seems to use a lot more oil. I used to run about 600-700 miles on a quart, which wasn’t great, but now it uses a quart every two hundred miles, and the oil cost is three times as much as the cheap stuff. It seems like I’m getting some oil leaks too, and the engine is ticking like the lifters are making noise. Do you think I hurt something? Should I just change back to the old 20-50 Valvoline I used to run?

Jonathan Kemp

Jonathan, I hope running that witches’ brew didn’t do any real damage to the engine. Those kinds of old-fashioned backyard tricks are okay if the engine is a junker that you really don’t care about, but this is not something I would do to my Demon, even if the engine is tired.

The thin synthetic oil is much more likely to leak when put in an older engine, and it will often result in oil consumption. Another problem is that many of these modern oils are formulated for roller cam engines, and do not have sufficient additives for a flat tappet camshaft like the one your engine has. The tappet noise is what really has me worried, since it can mean a camshaft that is going away. If that is the case, you may be looking at a rebuild before everything is back to normal. I would remove the valve covers and inspect every rocker for clearance while the cam at TDC with the valves closed for the cylinder being checked. I would look for wear or scuffing on the cam lobes. If there is excessive clearance wear in any of them, the intake will have to be pulled and the cam and lifters inspected more closely. The only cure here is replacement of both the cam and lifters. If everything looks fine, I would suggest changing oil back to the heavier mineral based lube, and keep my fingers crossed that the noise and oil consumption clears up.

...many of these modern oils are formulated for roller cam engines, and do not have sufficient additives for a flat tappet camshaft like the one your engine has.


I have a ’68 Dart, with a Slant Six for power. Unexpectedly, I actually like the car with the six. Eventually I am going to swap to a small block, and have been gathering parts. What I have so far is a 360 and 727 out of a ’77 Dodge truck. I pulled the 360 apart and re-ringed and re-gasketed it, and added a Crane 272 Powermax cam. I had a valve job done, milled the heads .040-inch, and added 2.02-inch intake valves and new springs. The engine was detailed, and it is now sitting on the engine stand with a Performer RPM intake and 750 AFB carb.

I cleaned up the transmission, and installed a shift kit. I also threw in a new filter, and think that is all it will need. For the rear, I had trouble finding an A-body 83⁄4 that fit my budget, but I found a complete A-body 81⁄4 and added a limited slip. The rear has 3.55 gears. I also got a complete K-member from a rusty V-8 Dart, along with the motor mounts. I have a few questions though. How much power do you think my 360 will make? How can I increase the rpm at which the transmission shifts automatically at wide open throttle? I know stock, these truck transmissions shifted at about 4,000 rpm with full kick down, and would like to step that up. Finally, do you think the 81⁄4 will be enough rear?

Peter Mason

Peter, I think the stuff you’ve gathered together will make a really nice street machine. A 360 like the one you’ve put together should make 320-350 horsepower with headers and offer very good drivability. The upshift speed of the transmission will be higher than stock, due to the increase in line pressure from the shift kit. If you want more, your best bet is to go with a higher upshift governor. As for the rear, if you’re planning on really beating it up at the strip with drag slicks, it might prove marginal. However, on the street with an automatic it will live a long and healthy life.