While we are talkin motors...

I love my 304. It crawles very well, it whines at high RPM's with ease, AND IT NEVER OVERHEATS. It also runs very well even though I haven't done a tune up in three years.

I know it will go out sooner or later and I would obviously drop in a 345 or 392... Or would I? I could probably find a 304 for about a hundred bucks.

I don't want to hear about higher HP at whatever RPM's. What I do want to know is how you feel about your IH motor. Does it work for you or not and in what driving conditions?

Thanks in advance. --JoshC

I would stay with the 304 or another 304 if you are happy with it. I use diesels, so my opinion would be biased toward them.

But, I have friends that have the SV motors in thier trail Scouts, and I can tell you what I have observed if that helps at all.

Scout 1 has a 304, 727, 4:56's, and 33's. He has no overheating issues, just top speed issues. Off-road he goes where any of the other guys go, and his rig isn't set up to near the level that the others are.

Scout 2 has a 345, T-19 Wide, 4:88's, and 37's. he has no overheating issues BELOW 85 degrees outside temp. Above that, he has his auxiliary fan on all the time to keep the boil-over from happening.

Scout 3 has a 392 Non-IC, T-19 Wide, 3:73's, and 35's with a tera-low in the DANA 20. His rig overheats constantly, no matter the weather when on the trail. Around town and on the road, it's fine, but warm. He has a 4-row radiator, auxiliary fan, big engine-driven fan, but no shroud ( I have told him that it would help, but cannot convince him).

Hope this helped.

304,345,392 all weigh about the same lbs. There are a ton of 392s at PnP for only 75.00! There is no replacement for displacement !!!

Got a 392 Non-IC w/345 heads, stock, no porting, no shaving, stock cam, stock manifolds.. blaa blaa blaa, T-19 wide, D300, 4.10's and 33's.


Rarely overheats, and thats on long, HOT trails creap'n around. Course, no shroud, clutched fan, leaky rad...

Plenty of grunt in the trails, just crawls around, plenty of power when I want to gas it.


Had a tired 345 in there when I killed the original motor (that is rebuilt and back in there now, lost oil pressure, my f-up, spun bearing, will tell story only over beer)

345 worked fine, 392 has more power, but then its fresh


Hoop had a 345, tossed in a 304 when he rebuilt the 345, 304 worked fine, but the fresh 345 had more power (duh).



Run what you got, if you like it, 304's are cheap (sometimes free, running), 345's are cheap, I'll well you a good short block/core for $50, 392's can be all over the spectrum, some people think they are gold, others, they are just another motor.


If I was building one, and had to get a core, I would seek out a 392 block (really, other than pistons, the internals are interchangable with a 345, and you will get pistons if you bore, so you can combine a 345 and 392), the proper 345 heads, exhaust ported, stock cam or one step up, chevy v-springs, if you want, I don't need them, my motor rarley sees the high side of 4K, and will do 5 with out floating. efi and ignition, or good carb (2bbl or 4) and ignition.

Take a 345 if you get one and have a hard time finding a 392, 304's are shorter stroke, so they *could* have the potential to rev higher, and do rev faster.


my ramblings

I have a stock 345 with alot of "bolt ons" - EFI, cold air intake, headers, good exhaust, with a T19 close box. It runs a little warm, actually runs hotter on the interstate at 65 than it does idling on the trail for 5 hours. It moves very well on the street, and pretty much crawls over anything the rest of the truck can handle, but it is my first IH motor. I kinda wonder how a 304 or a 392 with some well matched internal mods would compare to my setup.

I have a stock 70,000 mile 345, q-jet, GM HEI, t-19 wide, dana 300, 4.56's and 37's, i drive it to and from the trails (usally a few hours away), its never runs over 200 (no shroud, soon to have one though), it doen't seem to mind running at 4000rpm and it has never left me stranded (it been laid on its side once and all the way over once). I do have a 392 on the stand that when i get to it, it will be rebuilt and take the 345's place (only becouse the 345 is the only thing that hasn't been rebuilt on the rig) and the 345 will go into another project where it will most likely last a long time. I have a 72 1210 that now has a 304 in it it runs great and never over heats but when towing just doesn't have the power the tired 345 it replaced had, so another 345 is going into its place from a 73 scout.

I got no complant with my 304 idels over anything and runs like a top. I can let it sit for a few month and 3 hit on the pedel and she fires rite up at any temp and I can walk away from it. Kinda bugs my dad cuz that the main thing he brags about on his FI

When your geared over 100:1 in low range it really doesn't matter how many ponies your IH 266 or 392 V8 has...

Originally posted by Joe V
When your geared over 100:1 in low range it really doesn't matter how many ponies your IH 266 or 392 V8 has...

lol just slap in a 8HP Briggs and statton and call it good enugh


grate gas milage

I have a fresh 345 in my 76 Scout, works well with the 727 and 4.56's with 38's. It's a daily driver and I use it time from time to pull my Zuk.:)

I have a 304 in my '70, and a 345 in my '78. Both are 2bbl carbs, and both are bone stock, no modifying at all. My 304 I think is in a little better shape... always run excellent on the highway, and seemed a little bit peppier than the 345 to me. I have no complaints about the 345 though.

It's tough to compare. I'd like to have both blocks in freshly rebuilt condition to compare 'em, but there is no chance of that happening anytime soon. I'm looking for another 304 block that can rebuild for a daily-driver though.

Originally posted by JoshC
While we are talkin motors...

I love my 304. It crawles very well, it whines at high RPM's with ease, AND IT NEVER OVERHEATS. It also runs very well even though I haven't done a tune up in three years.

I know it will go out sooner or later and I would obviously drop in a 345 or 392... Or would I? I could probably find a 304 for about a hundred bucks.

I don't want to hear about higher HP at whatever RPM's. What I do want to know is how you feel about your IH motor. Does it work for you or not and in what driving conditions?

Thanks in advance. --JoshC

My 304 always seemed adequate. I built my 345 because I had a 345 core, and the cost was the same.. and no replacement for displacement, right?

345 got slightly better mileage (fresh engine). Both motors are/were known to get hot (the 304 burned itself up) in my Scout.

Yes, my 345 does more RPM and makes more HP than the 304, because I built it for multiple purposes.

I was realistic - at the time, my Scout spent far more time on the street than on the trail, so it's built for good mid-range.

Now I drive it to work/around town maybe twice a month aside from our monthly trail rides (it's always good to drive it to work a couple days before a run to make sure everything's still happy).

The extra RPM is handy on the street and the trail. Especially in the snow. :D

With 4.09s and 36s and just a 2bbl, it feels a little weak on the highway in 4th these days, but I don't like running 3rd past 4000rpm when I can't hear the engine over the tire hum. :D 4bbl would probably wake it up a bit more, but the 2bbl has always been reliable.

My 304 was rebuilt (and is about to be rebuilt again.. *sigh*) and certainly seems to like 5000+ RPM a lot more than the 345. It refuses to idle over anything though with the high-stall converter.

If you're happy with a 304, run it. Find another for cheap if you blow it up.

My Travelette runs a 345, which does pretty darn well for what it is. It's getting a built 392. Not so much for more grunt (which won't hurt), but because the 345 is an unknown motor, the lifters tick at speed (probably shot cam bearings) and I just don't "know" it..

So I'll build a 392 and be SURE it's going to stay together 2000 miles from home.

Plus, I'm building it for a few more RPM, which doesn't hurt when you're running 4.30 gears and 235/85-16s.