t_irwin145

So me and my dad are taking on the task of rebuilding his old 76. It has a 5.9L 360 V8 in it currently, but my dad is thinking he wants an I6 in it instead. Is this at all possible? I haven't been able to find any that are supposed to fit. If so, any suggestions on a specific one to get or a place to look? I'm not an expert and neither is he so please don't tear me up on this, just wondering if we can consider that option. Thanks.

Daniel Black

If you really want to go from the V8 to the I6 you should run an ad somewhere for a trade. Most people want to go from the 6 to the V8 so they'd jump at the chance to swap parts with you. The 360-390(FE) platform is very popular so I'd try and find someone with a 300 I6 truck that wants a big block. You're gonna have to drill out the rivets and change the frame perches, swap the radiators, throttle linkage, bellhousing (M/T) or the whole transmission if yours is an automatic as the 360 has the big block bolt pattern and the 6 uses the small block pattern. You'll also need the 6-cylinder ignition module off the fender because it's different from a V8, and you'll have to swap the exhaust systems out. A lot of work for a 6 but if that's what you want it shouldn't be that hard to achieve.

burnthelight88

First let me ask why he would want to swap? I love the 6 but I don't know that I'd swap backwards like that...big expense, big project and the 360 is a good motor. If you're thinking MPG, it's really not going to get a whole lot better, and the money you'd possibly save will be burnt doing the swap.

If you really want to, the swap with another person idea above is a great start. The 390 is more desirable that the 360, but they're both good motors and you'd probably get a good amount of interest. Otherwise I'd hit a junkyard and pull one. Could be a fun motor rebuild project.

t_irwin145

Thanks for the replies guys
He's thinking mileage mostly, because I'd be taking this to college. Also if you knew him once he gets an idea in his head its hard to convince him of another alternative so hopefully i can talk him down.
BTW anybody know what kind of mileage it'd get on the V8? Just curious.

artugio

Not awesome, to say the least haha. But it is somewhat dependent on the overall mechanical condition of the truck, how you drive it, etc. I have a 76 F150 with the 390 in it and it gets a solid 11-12 on a good day

burnthelight88

Mileage improvement would be negligible, and the money saved on gas would be lost performing the swap. It would take years to recoup the money in gas savings.

11-12 is achievable on the 390 with peak tuning and excellent maintenance. I don't think you'd see more than 14 on the 300I6 with peak tuning and maintenance.