Hey guys, new to the forum. I currently own a 1988 Volvo 740 GLE manual. Once the engine gives I plan on swapping to either a 5.3 or 6.0. My goal is between 400-500HP, while running forced induction. Plan on doing a cam swap, maybe new heads, etc. etc. I will be using the TH400 transmission as well as swapping out the rear end for an 8.8". My only current "issue" is deciding on either the 5.3 or 6.0. Is the price of the 6.0 worth getting over the 5.3? Any help or knowledge is greatly appreciated, thanks!

 

5.3 vs 6.0 is a toss up. Shouldn't be to much of a difference just maybe a little more HP. I believe the 5.3 has more mod options so I would consider it instead of the 6.0. As far as the autobox I wouldn't go with a 400 but get a upgraded R700 because of the OD capability. Also with that much HP the 8+" rear would be a good start and make sure you get an aluminum one piece drive shaft. Good luck and have fun.

 

Thanks for the info! Most of what I have seen suggested the 5.3 just because they are so common and fairly close with HP. I think the 700R4 transmission would be good beefed up, I am assuming many people have used this transmission with the 5.3? OD would be a plus IMO just for what I'll be using the car for. And I will definitely look into the aluminum one piece drive shaft. Thanks again!

 

"once the engine gives".... the B230F engines have been known to run 500K+ miles and still have decent compression etc (generally the chassis starts rotting away before the engine gives out)

 

Oh man, mine has 387k with no signs on going bad, just figured it was going to happen sooner or later LOL. the chasis is rust free, and this engine burns no oil whatsoever... Suspension will need a little work but I plan on upgrading to coilovers once the process starts.

 

From what I know, that chassis is not designed to support the structural load of that kind of horsepower. You have to consider that this is a car designed for about 125 HP or so. I can't imagine how much it would cost to retrofit adequate drivetrain components and a tubular frame to keep it all from twisting.

I knew a guy when I lived in Ohio who just had to put a high horsepower engine in a stock 70s era Mustang. The windshield was cracked and the roof buckled from the torque. The rest of the car was not structurally ready for super power. Anything south of 250 horsepower probably would have been okay but he went over the top.

Car ruined, money wasted.

 

huh, aren't vintage mustangs full frame cars? engine, suspension, rear axle, all attached to the frame, and the body floats on that frame?

 

Thanks for the input, I will keep researching. I have seen a fairly large amount of 240's with LS, 2jz, etc swaps and haven't heard any mention of a weak chassis. I've seen a few (not as many but still a good amount) of 740 conversions that had the same swaps with no mention of damaging frames from the power. I hope it is not the case, but then again, I will keep looking. I bought the car a long time ago for $800 as a daily from work and back and figured it would be fun to swap. If push comes to shove I'm sure I can find an old 240 and do my swap there. If you have any links or more information about the frames please share with me, thanks!

 

It was a 1978 Mustang. From what I know, the Mustang has always been unibody construction. Since the car had a 302 as an option, the thinking was to put a bigger engine with lots of power. Mission accomplished. Car did not take the twisting of the additional torque.

 

All Mustangs were/are unibody. The initial ones were built on the falcon chassis but still welded sheet metal.