5.3 VS. 5.7 Bowtie?

[Keith__C]

Close Don, Its a BOSS 429 Jon Kaase is making a reproduction of them. Sorry that it's not Jeep Related but I'm answering a Question. BOSS 429 is considered one of Ford's Hemi's (in reality it is a Polyspherical-I'll explain this part later) There actually are a Ton of Hemi-style motors out there (The Toyota IForce V8 for example) Hemi motors have been around for alot longer than Chrysler has, Chrysler just owns the patent to the slogan "Hemi"
Here's a short article on that Boss 429 which after a dyno pull of 900 Hp & 800 ft. lbs got stuffed in a mustang. Jon Kaase Racing Engines - Kaase Boss Nine 589 c.i. 2008 GT Mustang --Note the capable of over 1900 HP. IHRA and UHRA (Monster Trucks) both run these motors at the 2000+ Hp very regularly The SOHC 427 is Fords other Hemi. SOHC 427's are very rare and very valuable and totally anhialated the 426 Hemi in EVERY aspect. the 427 SOHC is also the first motor to produce over 8000HP. Factory they were rated at 650HP and LOVED to spin 7-8K RPM all day long (and this is in the days of MASSIVELY under-rating your engines) Enough to make Dodge through a temper tantrum induced hissie fit to the NASCAR Board and threaten to boycott Nascar unless the SOHC was immediately banned after a Galaxie with it ran the fastest qualifying lap time EVER at Daytona and held onto that record for a VERY long time, with all the rules in place today it may even still hold the record. Long story short at the time Nascar banned all Hemi-type motors since both the 426 and 427 SOHC are Hemi's after Dodge's hissy fit, which never allowed the 427SOHC to run anything more than a qualifying run leaving the 426 Hemi Charger Daytona as the "Historic car of Nascar" That only left the 440 wedge head pitted against a 427 High rise Ford which was an even bigger joke of a comptetition (Ford really did Dominate the Hp war of the 60's they just never put enough of them out to make a strong showing, actually the HP war was between Ford and Dodge since Chevy had nothing to bring to the table making any kind of real HP) Again Ford dominated, Dodge threw hissie fit, eventually Left NASCAR altogether and stuck to Drag racing, NASCAR banned all big cubic inch motors in the early 70's just as Ford was developing the BOSS 429 to race in Nascar with (a "Polyspherical" type engine to get around the Hemisperical ban) After the BIG cubic inch ban Chevy took over with the small block 350 and NASCAR became the joke of racing it is today. The 427 SOHC and 426 Hemi have thrown down repeatedly in Drag Racing (withthe SOHC winning most of them) and if it wasn't for the 7' long timing chain required to operate the 427 SOHC they would probably still be doing it today. Here is a Youtube link to a 427 SOHC

 

[Muskoka]

> Yes, I know this is a dead thread but you never know who's going to stumble in here, read it and go
> away believing it; worse still, start preaching it.
>
> I have no doubt the author of the post parks at least one Ford in his driveway, and is therefore self-appointed to resident expert.
> Sorry, but when you lay your condescending drivel on that thick it's bound to get noticed and in this case addressed.
>
> Quote: "the 427 SOHC is also the first motor to produce over 8000 HP".
>
> In a word...WRONG!
>
> In 1970 the most powerful Top Fuel engine of the day was Gene Snow's HEMI powered RAMBUNCTIOUS
> FUNNY CAR. It produced an astonishing for the time 1800 (eighteen-hundred) horsepower.
> The Ford engines were already gone from the nitro ranks. The Ford's could not survive nitro.
> At the 1200 horsepower mark the 427 Sohc was suffering serious mechanical problems.
> At the 1500 horsepower mark the 427 Sohc was a grenade that oiled down the track.
> The sanctioning bodies got tired of cleaning up after the Sohc and it was forbidden to run nitromethane.
> Relegated to the alcohol ranks, only the diehards continued to bother with the Sohc.
> The only competition the 426 HEMI had in Top Fuel was from Chevrolet's RAT motor.
> The Chevy RAT actually won some races as horsepower levels were competitive and continuing to rise.
> At about the 2300 horsepower mark the weakness of the RAT finally manifested; the cylinder heads
> were blowing right off, in big expensive chunks.
>
> You see it's not the engine developing the power with nitromethane. It's the fuel. It's like running an
> engine on dynamite.The engine is the means of delivering the explosive forces of this fuel to a crankshaft.
> This cannot be done if you don't have "containment". The superior architecture of the Chrysler designed HEMI
> provides that containment.
> The inherent weaknesses of an engine design cannot hide from the stress of running nitromethane.
> Nitromethane has no problem at all exposing the design flaws of any engine.
> Just about every 427 Sohc that ever ran nitro split the engine block or blew it to smithereens.
> The only engine the 427 Sohc ever annihilated was itself, everytime it ran nitro.
>
> For a brief period of time an engine from Australia called the McGee competed against the HEMI.
> The McGee put on a good show and won some events. The McGee was also a "cammer", and a much
> superior one to the Ford 427 Sohc.
> The McGee reached ouput levels of up to 5000 (five-thousand) horsepower and it kept the HEMI busy.
> NHRA rule changes rendered the McGee no longer eligible for competition leaving the HEMI alone in
> Top Fuel.
>
> NHRA's Top Fuel regulation engine is to this day based exclusively upon the 1964 A864 426 Chrysler
> factory race HEMI.
> It develops 10,000 (ten-thousand) horsepower and 7,200 (seven-thousand two-hundred) foot pounds torque
> at half track. If you watched the GATORNATIONALS on Wednesday March 16, this information came up in
> the NHRA commentary.
> In simple arithmetic that's 8800 horsepower that the 427 Sohc never saw and it's a safe bet never will.
> I subtracted 1200 from 10,000 as opposed to 1500 because at 1200 the Sohc was still a running engine.>
> At 1500 it was shrapnel.
>
> This would explain of course why the link to the You Tube- Starting a blown alcohol 427 SOHC is significant
> because the 427 SOHC will at least run on alcohol.
>
> HEMI is not a "slogan" by the way. It's a registered trademark. HEMI is HEMI®.

 

[extra-medium]

go with a 5.3 and a 4l60e, mp 242 t case, and dana 44 axles. I saw something about a v8 swap, and came across this. Jeep – The Polar Bear - Cody Brown.com
I know its a ZJ and you have a yj, but you would have probably just as much room to work with. You could also just go with a chrysler based v8 so it would be easier to put in and connect up.