Wow we got 3 pages of posting all because a guys said 325 instead of 320...all that nit picking over 5Hp as if it even matters...that is such a small amout that it really would make any differance either way.
I was chastised on anoher thread recently for posting "wrong" info (that was gleaned from another site)...And was told that post bad info is not allowed here...and RUSS was involved that that thread aswell! So I am doing my best to keep these boards CORRECT!
Point was that he said it had ATLEAST 325hp...indicating that some 68/69 390's had MORE than 325, NOT TRUE...and apparently NOT ALLOWED!
BTW EGO....for the 12th time...it is not about how much power his engine has, he wanted to know the factory rating of it...I think he and everyone is well aware of the under rated motors and that they never produce EXACTLY what they are rated for, and that no two engines are ever the same...etc..etc..
BTW, We would actually need to know the exact application and year to find its original hp rating!
Last edited by fomocofan : 07-15-2006 at 05:31 PM.
Dude it doesnt matter if it was 325, 320 or 330 there all so close that nobody would ever be able to tell the differance without a dyno and since things werent that accurate back then....who knows 5hp could just be a marginal grey area of give or take. Im sure he got the point 320...325ish...its all the same.
Dude it doesnt matter if it was 325, 320 or 330 there all so close that nobody would ever be able to tell the differance without a dyno and since things werent that accurate back then....who knows 5hp could just be a marginal grey area of give or take. Im sure he got the point 320...325ish...its all the same.
Actually the GTs were all identical. Same block, pistons, rods, crank, cam, valves train, heads, exhaust, dist., intake and carb. Just rated different so they could claim it was new for that year.
So what you guys are saying is that my 68 F-250 with the 390 4V had either 320 0r 325 HP..But because I had power steering and power brakes and an altenator it probably only had, what about 315 or 310? I just remember that it always got my fith wheel to were we wanted to go, with no problem....
So what you guys are saying is that my 68 F-250 with the 390 4V had either 320 0r 325 HP..But because I had power steering and power brakes and an altenator it probably only had, what about 315 or 310? I just remember that it always got my fith wheel to were we wanted to go, with no problem....
Only if it was the GT motor with the GT cam grind. That was the one part that separated the GT 390 from the std 390 4 bbl motor. Same cam was also used in the 428CJ, 68 427 (390 horse hyd cam.) and I believe the 428PI hydraulic cammed motors. Otherwise the 390 4 bbl engine used all the same parts, other than the carb and exhaust manifolds, but those two made little if any difference.
So what you guys are saying is that my 68 F-250 with the 390 4V had either 320 0r 325 HP..But because I had power steering and power brakes and an altenator it probably only had, what about 315 or 310? I just remember that it always got my fith wheel to were we wanted to go, with no problem....
No 1968 F250 came from the factory with a 390 with other than a 2 barrel carb and a low compression motor rated a 255 hp. The 4 barrel was added or the motor swapped by someone at a later date. So without a teardown it is impossible to say what motor you have.
After nearly 40 years that 68 F250 could have anything under the hood Who knows, could be a 427 or 428CJ or super CJ. I had a friend in high school ( mid 70's) that had a LWB F100 with a 390/4speed Toploader, he ran across a guy just outside of town that he bought a 3x2 intake from. In the guy's shop, sitting in a crate in the middle of the floor was an SOHC 427. He told me he tried his best to buy the SOHC, but the guy wasn't selling. When I asked what he wanted the Cammer for, he replied: "Put it in my truck, what else?"
Last edited by baddad457 : 07-16-2006 at 12:14 PM.
So the 414 I installed in my 68 CS with 427 LR heads (9.1 cr), 428 CJ cam, headers and 670 Holley should make a little more power vs truck 390's at 255 hp?
So the 414 I installed in my 68 CS with 427 LR heads (9.1 cr), 428 CJ cam, headers and 670 Holley should make a little more power vs truck 390's at 255 hp?
So what you guys are saying is that my 68 F-250 with the 390 4V had either 320 0r 325 HP..But because I had power steering and power brakes and an altenator it probably only had, what about 315 or 310? I just remember that it always got my fith wheel to were we wanted to go, with no problem....
I know Bear already answered you correctly.
The reason I was being sooo picky is because some people like yourself (no offense meant) like to think that because one 390 4bbl made 325ish hp that your 390 2bbl/4bbl would make just as much...
It obviously depends on EXACTLY what year and version you start with...as to how much you can guestimate on you rough hp...
Some 390 2bbl were essentialy the same as the 4bbl motors..and adding a 4bbl could make as much if not more than the std. 4bbl engine...
Botton line is it is good to know what your engine is and what it was rated for originally...then you can have a baseline to build on.
I think alot of good info came out of this post...
I apologize if I rub some people the wrong way, but if nothing else I always get people to dig down and we always seem to uncover the facts...I am always pleased when we eventually get the straight scoop out and come to a consensus!
Oh, BTW...you have to remember that in the pre '72 days engines were not rated the same as they are now..
I think someone already posted the details, but the hp numbers back then were (i believe) at the crank w/o accessories...you always lose alittle hp when the accessories are installed over the rated hp.
Post 72 engines are rated with accessories installed.
A post 72 engine rated at 300hp will have more power than a pre 72 300 hp engine, for example.
Last edited by fomocofan : 07-16-2006 at 05:22 PM.
With the built up carbon over the years you might as well minus 15hp of that. I don't know why people worry about paek hp numbers. I will take a 400ci engine that has 250hp at 4500 and 52 at 1000rpm before a 140ci engine that has 280hp at 7100rpm and 21hp at 1000rpm.
I got the vibe that someone dissed a 290hp 302. That happens to be the boss 302, take a look at those heads, intake, carb, and camshaft and tell me they can't run with a 428cj. Keep it in the powerband (4000-8000).
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Who knows, could be a 427 or 428CJ or super CJ. 
I had a friend in high school ( mid 70's) that had a LWB F100 with a 390/4speed Toploader, he ran across a guy just outside of town that he bought a 3x2 intake from. In the guy's shop, sitting in a crate in the middle of the floor was an SOHC 427. He told me he tried his best to buy the SOHC, but the guy wasn't selling. When I asked what he wanted the Cammer for, he replied: "Put it in my truck, what else?" 
