7.5" rear behind a 455?

[Bonnewagon]

unless you drive like a maniac

Yeah those days are gone. I've broken too many expensive parts that way and I am tired of fixing my mistakes. I should add this 455 is totally stock for 1976. I am pretty sure the cam is the 067 so it is no screamer. The 400 I ran had a very lumpy cam and probably made lots more power than this 455 in it's present state.

 

[spidereyes455]

Mark you are correct. Every thing I have ever seen says that 75 and 76 455's are identical. I have a 75 455 laying around (you got the valley pan from it) and when I tore it down for an inspection it did indeed have an 067 cam in it.

 

[lilbowtie]

All I’m saying is for a cruise car with street tires that DOESN’T get abused, that 7.5 will/can handle it.

I can't agree with you more - but - I wouldn't consider taking it to the strip w/ slicks (ET streets) treating it right and not abusing it. I also should have said you have the potential for a 11 sec car. Now if your only running the 12.90 range your only throwing a about 320 hp to the rear tires.

 

[tc1959]

Drive it,

 

[icr242005]

Well all I’m saying is I did and my little 7.5 has taken it fine. I never said I was taking easy on mine lol, Original author said he was not going to beat on his. Now I’m not getting caught up in the BS about “sooner or later it will blow” cause you don’t know, I don’t know when/if it will blow, quite frankly nothing last forever. There is no possible way for u to know how much horse power it takes to make a 12.90 pass without even know my set up. Like car weight wheel size, finial speed, However u could google guess it which I’m assuming you did.

 

[Texas82GP]

Well all I’m saying is I did and my little 7.5 has taken it fine. I never said I was taking easy on mine lol, Original author said he was not going to beat on his. Now I’m not getting caught up in the BS about “sooner or later it will blow” cause you don’t know, I don’t know when/if it will blow, quite frankly nothing last forever. There is no possible way for u to know how much horse power it takes to make a 12.90 pass without even know my set up. Like car weight wheel size, finial speed, However u could google guess it which I’m assuming you did.

Drag racing is his hobby. He does know something about it. He has a fast SBC powered Regal. If you know the weight, the HP and the distance, it is pretty to make an educated guess on the time.

 

[icr242005]

never once did I give my wt or speed. That’s my point. Not enough info to guess. But I’m done with this. Going back to original authors question. IMO a 7.5 is a strong little rear end that can handle “some” abuse.

 

[art]

I have run 7.5's behind hot small blocks and big blocks. Open, posi, and a powertrax equiped unit. The one that broke? Behind a 307 Olds ! Had 4.56's in it and a bit of wheel hop knocked teeth off the ring and pinion.

 

[icr242005]

Lol. That sucks. The 30 year GM mechanic that set my rear end up has a 7.5 in his street/drag car. He said he was going to run until and that was 10 years ago. He did recommend a housing girdle which is going on this winter. He also said that’s what takes most of them out is the gears separating and knocking teeth off.

 

[olds307 and 403]

I broke a no slip at the track with slicks then exploded the open spider gears on the street, took out the pinion with a 8 to 1 403 that ran a lousy 9.7 in the 1/8. The Yukon replacement open spider gears held up to a 9.4 in the 1/8 with the 350 on slicks. Any serious power is gamble on these spindly 7.5's. A girdle cover doesn't stop exploding pinion gears, mine didn't.