ALWAYS THE BOSS-MY FAVORITE FORD!

during the muscle-car era for produce a ton of muscle-car small blocks today we're gonna take a look at to my most favorite and my least favorite let's check them out as I promised in the intro today we're going to take a look at two different motors my favorite and my least favorite starting with the favorite now in 1971 a lot of the manufacturers had already started lowering the compression on their combinations everyone thought the muscle car era is over everyone except for for actually 1971 was the high-water mark for Ford performance you see in 71 they combined the boss name with the 351 cleveland giving us a boss 351 and in 1971 despite the fact that everyone was lowering the compression that boss 351 had 11 to 1 compression in 1971 and it turns out it's the most powerful small-block I've ever tested that's one of the reasons I wanted to test build and test all of these combinations you see you can't test other guys you can't test acceleration runs from back in the day because you never know what you got I wanted to find out what they all do test it under the same conditions so with a great effort to test all of these small blocks and I can tell you this until I test something else that makes more power and I've tested a ton of Chevy's and a ton of Ford's that 1971 boss 351 makes the most power of any factory small-block I'm ever tested the only one I think that might have a chance is the 346 pack offered by dodge now I've seen some other tests but those are modified versions so until I test the stock one are you listening Steve dole such until I test a stock one right now boss 351 high-water mark for all the muscle car small blocks now let's check out the motor that I really don't like if the boss 351 is my favorite what is my least favorite oddly enough it's a hi-po 289 that's right you guys let me know tell me all the stories you have about the super cool super fast high revin hi-po 289 to rant i want to hear about it because maybe i'm not giving it a fair shake but I can tell you this I was an owner I had a really cool in 1965 for speed for series gear Mustang GT with a hi-po 289 it even had the Shelby upgrades it had the Tri white headers it had the aluminum intake it had a Holley four-barrel and guess what at the same time I also had a van new 1988 5 liter 5-speed LX Mustang and you know it obviously I couldn't drive them both but I would bet that 5 liter Mustang in stock trim would kick the crap out of that hi-po 289 that's just the way I felt and lucky for you guys I'm actually gonna overlay those two power curves now the hi-po 289 obviously was rated at a much higher part power output you know 271 gross horsepower versus 225 net horsepower we're gonna take a look at the power at the differences in the power curves we're also going to compare the hi-po 289 to its shelby version because while i had it on the dyno i ran it in both trims but you guys let me know i'll show you what the power curves are and i'll tell you it's just not that impressive now i know back in the day all those Mustangs were fairly lightweight especially a shelby and next to a boss 351 body style that Shinoda body that's 65 and 66 fastback Mustang especially she'll be my next favor but that's not enough to make me like that little 289 tell me what you think let's get to our test Oh what is the most powerful high and simultaneously my favorite muscle car small-block at least in terms of Ford is the boss 351 and it's produced in 1971 that's right before after most people went away from the high compression Ford retained it in 1971 and still had 11 to 1 compression in the boss 351 not only that they had cleveland 4v heads on this thing which as we saw in our boss 302 video those head slowly they can make a lot of power and and in my opinion if anything they're even more at home on the 351 display symptom they were on the boss 302 takes nothing away from the boss 302 obviously awesome motor and it's kind of a toss-up for me between the boss 302 and the boss 351 only because I like the body style of a boss 351 Mustangs so much far and away my favorite body style now the boss 351 Mustang was a radical departure a lot of guys love it like I hate it but actually they're one of the reasons why I like the boss 351 so much is because it's the underdog guys don't like that as much as they'd like the boss three or two that Shinoda body styled Mustang it is awesome but guys don't seem to like the 71 as much but that's why I like it because it's an underdog and when you talk about boss motors everyone talks about the boss 302 or then the boss 429 big-block not very many guys talk about the boss 351 but guess what they should be because it's an awesome motor and not only that it's the most powerful factory small-block I've ever tested and I tested a ton of them so on this application we put together the boss 351 I put her put together replicas obviously I don't have the budget to forward to do a numbers-matching motor especially when you consider and we'll talk about this in a minute the induction system a an original auto light carburetor for this boss 351 might be a four or five thousand dollar carburetor just for the carburetor that's why I didn't have the budget to put one of those on there and I used the same same 750 Holley but I used on everything else now on this application the 750 Holley was fine and worked well and the auto light was not would not be under size and probably restrict power at all on this but the other thing I did that I had to change was the intake manifold I want you guys to let me know what you think in the comments I ran a cast-iron intake manifold now I'm told by lots of guys that the cast iron intake and the in the aluminum intake are identical internally the passengers are the same I don't know if that's true or not because I've never had that was another thing I had a hard time finding is a factory original boss 302 351 intake again another UNICOR like that I like carburetor very expensive and hard to find and I couldn't find one that I needed so that I could borrow it for the test which I borrowed a lot of parts for this because let's face it there's no budget to build this kind of motor but I built this boss 351 replicas it had the right camshaft in it I had a reproduction of the factory boss 351 cam and it had the right 4v cylinder heads at 11:1 compression it basically had everything it needed we ran it with long tube headers just like we did with the boss 302 it just had the cast iron 4v intake and that Holley carburetor but you quit this that's much much in the way that we ran the boss 302 and the other small-block Chevy's this thing produced three hundred and eighty-three horsepower and also impressive 391 foot-pounds of torque and that's a lot of power especially if we compare it to other things that were happening during that year and and I'm gonna compare right now to a 1970 small-block Chevy and lt1 350 again close to being my favorite small-block Chevy because my first car when I was growing up when I was 16 was a 1970 and a half split bumper rally sport Camaro now is not a z28 which would have had the lt1 in it but it was a split bumper it was a seventeen and a half so I kind of have a soft spot for that lt1 I wish I had one so if we take a look at a comparison between that 1970 high compression lt1 and this boss 351 you see that the boss 351 actually made every bit as much torque has that lt1 but just made a lot more power out on the big end now you can thank the high flowing 4 v cleveland heads for that because those heads flow you know 50 or 60 CFM more than the LT 1 hits so they both had high compression and they both had good camshafts they both had you know good induction systems so I think you can point to the 351 the boss 351 able to use all of the head floor at least a good part of the head flow from those amazing 4v Cleveland heads so now that we've take a look at maybe my favorite ford ford small-block muscle car small-block let's take a look what's probably my least favorite now I can take a look at what is maybe my least favorite all these muscle car small blocks that I ran and this was actually a hi-po 289 and you guys can tell me if you think I'm wrong about this but I actually had a 1965 Mustang GT you know it was the right kind of car was a four-speed for series gears with a hi-po 289 even though the Shelby upgrades on it it had the aluminum intake at Holley and try white headers so it was done upright but I can tell you that it sure didn't feel very fast and I know I also had my then new 1988 5b relics Mustang and that 5b relics Mustang would definitely beat the Shelby or definitely be that hi-po 289 so guys tell me if you think that that's the case I'll show you a power curve difference here but when I ran this reproduction of the hi-po 289 you don't manage to produce just over 280 horsepower 281 horsepower and a little over 300 foot-pounds of torque and when I compared this to the other muscle cars more small blocks of the air especially you'd like the boss 302 and the boss 351 the Ford side it's just not you know it's just not terribly impressive and I know if we compare it to you know a 5 liter 302 rated at 225 horsepower this looks like a lot more but if we actually compare it to a 5 liter motor the way that we run it on the engine dyno the way that we run this we can see that there's a big difference obviously out at the top the hi-po 289 it's got a lot more camshaft and wants to rev higher it's got that carbureted intake and and then on this hi-po 289 i think it's worth noting I ran a Holley carburetor on not the auto light because we didn't have access to the factory auto light carburetor but if we compare this to a you know 1989 90 91 5 liter Mustang engine a stock one with a long runner intake and this one was run with headers on it but that one only managed to produce under 260 horsepower 258 horsepower but here's what really makes it feel good is the difference in torque down in the 3,000 to 3,500 rpm range I mean we're talking about we're talking about a difference of you know 30 or 40 foot pounds of torque it's quite a bit so it feels a lot better and obviously you're early shifting on the on a 5 liter it just felt like it was a lot faster I never obviously could drive both of them to Drag Race them but that factory 5 liter sure felt like it was a lot better but in addition to running the hi-po 289 we also ran it in shelby guys so we put the aluminum intake I didn't have a 715 Holley so we ran a 750 Hall and we used the try wife Shelby headers on this 289 and here's what happened and it did indeed like I you know those the guys at Shelby knew how to make power obviously they don't want a lot of Road Race champions and stuff with with their accommodation so they knew how to build power even back then so that combination pushed the hi-po 289 over 300 horsepower shall be rated at 306 we didn't quite make that much we made 302 and torque was up to that through most of the curve 310 foot-pounds of torque so that was being a little bit more respectable now I hear a lot of comments from guys and I want you guys to make the comments about guys revving these things out too you know you can pick your number guys they're saying eight nine ten even ten thousand rpm which you know maybe maybe guys really did back in the day but my concern for these wouldn't be the fact that you could put a roller cam in and enough spring and valvetrain stuff in it it's just that these cylinder heads only flow you know 160 or 170 CFM and I just can't see them making power out that rpm range now maybe if you put a really big set of ported heads I mean a 289 is small by displacement comparisons you know compared to the 302 and the 351 that of it and 327 that the other guys were using but it also didn't have much head flow so if you put a air flow research or a trick flow head on this it would be a lot better but it would still only be 289 cubic inches so it always had a deficit the one thing it did have going for it is if you put this motor in a 65 or 66 fastback Mustang which is awesome they were pretty lightweight so that helped them obviously with the power-to-weight ratio but let me know you guys think 289 nah I'm not a big fan like the boss 302 and the boss 351 much better let's get to our conclusion ok guys what do you think about our test is the boss 351 really the most powerful factory muscle car small-block ever produced if it's not what do you guys think it is for me it's awesome lots of head flow and nut displacement compared to the 302 it has enough camshaft it has enough compression of course I can't afford the five or ten thousand dollar auto like carburetor and unicorn aluminum intake manifold but that's beside the point guys that have boss 351 already have that stuff and obviously they work well what about the hi-po 289 they not give it a fair shake should I really like that should I take another look at it here's my problem I kind of choose these based on the power potential and a boss 302 or in this case a 351 has a cylinder head that flows a ton a hypo 289 has a cylinder head that flows almost nothing I mean a boss head out flows that hi-po 289 head by probably a hundred CFM per cylinder per cylinder that's a lot so while the boss is just scratching the surface of the potential of that head the hi-po 289 is using almost all of that head and maybe that's why I don't like it cuz it doesn't have a ton of potential but let me know if I'm wrong thanks for watching guys make sure to like share subscribe ring the bell let me know I'll keep testing

Channel: Richard Holdener

Views: 62,676

Rating: 4.9431715 out of 5

Keywords: BOSS, 351, SMALL BLOCK, 289, HIPO, MUSTANG, SHELBY, V8

Id: ptWHg0e-21k

Length: 14min 8sec (848 seconds)

Published: Fri May 22 2020