[besserspat]

I was casually looking under my 73 bird today and I was amazed by the amount of engine/transmisison offset to the passenger side there was.

I barely have 3/8" clearance between the U joint and the transmission tunnel on the passenger side while having tons of it on the driver side.

It got me thinking a little, since I plan on installing a 3.5" driveshaft with 1350 U- joints on the car next winter. I dont think It'll fit...

I know the engine was quite a bit offset to the passenger side on 67-69 birds...but second gens? and as much??

see pictures..

[78w72]

3/8" seems rather tight, ive never measured mine but they werent that tight, will have to look next time im under there. many times the frames on these cars can be tweaked causing the shaker to be off center, but the driveshaft that close is a new one to me.

for the 3.5" drive shaft, how much power are you making? for any street car or even 500+hp drag strip use, every shop i contacted for info/pricing on a d/s including strange, they all said 3" cromo was more than enough, some said 3" DOM would b e fine at my power level, its the 1350cromo yoke that is the benefit. so unless you are making 600+ with slicks & a tranny brake i doubt you need a 3.5" d/s.

[besserspat]

Originally Posted by 78w72

3/8" seems rather tight, ive never measured mine but they werent that tight, will have to look next time im under there. many times the frames on these cars can be tweaked causing the shaker to be off center, but the driveshaft that close is a new one to me.

for the 3.5" drive shaft, how much power are you making? for any street car or even 500+hp drag strip use, every shop i contacted for info/pricing on a d/s including strange, they all said 3" cromo was more than enough, some said 3" DOM would b e fine at my power level, its the 1350cromo yoke that is the benefit. so unless you are making 600+ with slicks & a tranny brake i doubt you need a 3.5" d/s.

I have a driveshaft for it already its a 3.5 Chromo , billet yoke 1350 shaft We used on our race cars ( Hendrick's motorsports NASCAR overstocks). But I can always keep that one for other projects I have in the shop.

As for the powertrain waiting to go in its a Stroker 461, SD performance CNC heads, Hybrid version of the OF Cam HR-SR lifters ,( 500-525 hp) TH400 , 10" Continental 3200 (JH special) and a 200hp shot of nitrous. Will run DOT Slicks.

just a tame week end warrior.

[ta man]

Mine is tight as well..that's why when I went with a new driveshaft I went with a 3 inch CM.

[78w72]

Originally Posted by besserspat

I have a driveshaft for it already its a 3.5 Chromo , billet yoke 1350 shaft We used on our race cars ( Hendrick's motorsports NASCAR overstocks). But I can always keep that one for other projects I have in the shop.

As for the powertrain waiting to go in its a Stroker 461, SD performance CNC heads, Hybrid version of the OF Cam HR-SR lifters ,( 500-525 hp) TH400 , 10" Continental 3200 (JH special) and a 200hp shot of nitrous. Will run DOT Slicks.

just a tame week end warrior.

pretty close to my combo except no nitrous, same parts but 467 E-head, runs low 11's @120-123 on M/T drag radials on a suspension not set up for drag racing & fuel starvation issues... on a stock driveshaft with moog solid ujoints! will be buying a new 3" cromo/1350 shaft if i do any more drag racing.

i forget the exact number but strange said their 3"CM & 1350 was good for ~700+hp. my local shop using 3" DOM & billet 1350 said they've never had a problem on drag cars into the 9s & all kinds of high power/blown monster truck pullers & mudboggers that are popular in my area.

[25stevem]

It does not take much offset at the point where the motor mounts bolt to the frame for things back at the tailshaft near some 6 ft away to be very offset!

The only amount of offset you need is that which the nose of the pinion gear is from the left to right center of the differential.

[besserspat]

Originally Posted by 25stevem

It does not take much offset at the point where the motor mounts bolt to the frame for things back at the tailshaft near some 6 ft away to be very offset!

The only amount of offset you need is that which the nose of the pinion gear is from the left to right center of the differential.

Good point, last year I replaced the "collapsed" passenger side vulcanized rubber mount, cuz the passenger side header was literally resting on the subframe. Once the mount replaced with a "high quality"chinese anchor mount the engine sat where it should.

But since I only replaced the passenger side , maybe the driver side is getting tired and sags a little , throwing the th350 tail to the opposite side.

[besserspat]

Originally Posted by 78w72

pretty close to my combo except no nitrous, same parts but 467 E-head, runs low 11's @120-123 on M/T drag radials on a suspension not set up for drag racing & fuel starvation issues... on a stock driveshaft with moog solid ujoints! will be buying a new 3" cromo/1350 shaft if i do any more drag racing.

i forget the exact number but strange said their 3"CM & 1350 was good for ~700+hp. my local shop using 3" DOM & billet 1350 said they've never had a problem on drag cars into the 9s & all kinds of high power/blown monster truck pullers & mudboggers that are popular in my area.

That would be the kind of numbers that would make me happy, 118-120 in the quarter is quite respectable for anything with a licence plate.

The 200 shot is for playing around with bigger fishes.

What seems to work on my cars that are experiencing fuel starvation is installing a surge tank in the nose of the car, homemade or aftermarket.
You could have a 7/16 fuel line and stock pump to the surge tank and still run impressive ET, since most surge tanks are large enough on their own to supply fuel for a complete quarter mile in a really fast car.

Some people dont feel safe driving with a gallon of fuel hiding in the front of the car but my old 911 has all of its fuel in the nose...

[AG]

If you have the driveshaft already just see how it fits.

[besserspat]

True , Thats what I was doing to do anyway , but right now the car is a Th350 (27 baby splines) and the transmission that will get swapped in along with the 461 this winter is a Jake's built TH400 (32 splines). I may end up switching to clamshell or even solid motor mounts when the 461 gets swapped in, that may straighten things up a little and give me a little more hood/air cleaner clearance.

[AG]

The TH400 input yoke won't change the centerline so it's a matter of whether the 1350 U-joint is too close to the tunnel at the rear. The DS won't move laterally so a mm is a mile.

[besserspat]

Originally Posted by AG

The TH400 input yoke won't change the centerline so it's a matter of whether the 1350 U-joint is too close to the tunnel at the rear. The DS won't move laterally so a mm is a mile.

All I mean is that I was more enquiring about the normalcy of the TH350 tail being so much to the passenger side on and early second gen bird more than asking how could I fit a 3 5 DS in that space. I mean if I can get away with a smaller diameter and cheaper driveshaft at that Hp level im all for it.

I may stop by at my warehouse and pick up that 3.5 DS and mock it over the TH350 if I have time to spare. But I would bet that without straightening anything , the 3.5" CM driveshaft and 1350 joints would take it a little too close and having to tweak my DS loop.

But thanks for all the good comments so far!

[JUDGE3]

I would rethink the 3.5 huge driveshaft.

1350 u joints/yoke is a strong upgrade though. I used my stock driveshaft and had my driveshaft shop cut it and install 1350's and also went with a forged sonnax tranny yoke. my moser rear has the 1350 yoke as well.

[ta man]

All the money spent and reused the stock shaft? Why?

[78w72]

Originally Posted by besserspat

That would be the kind of numbers that would make me happy, 118-120 in the quarter is quite respectable for anything with a licence plate.

The 200 shot is for playing around with bigger fishes.

What seems to work on my cars that are experiencing fuel starvation is installing a surge tank in the nose of the car, homemade or aftermarket.
You could have a 7/16 fuel line and stock pump to the surge tank and still run impressive ET, since most surge tanks are large enough on their own to supply fuel for a complete quarter mile in a really fast car.

Some people dont feel safe driving with a gallon of fuel hiding in the front of the car but my old 911 has all of its fuel in the nose...

i looked at the robbmc surge tank, but like you said, i dont see that being a good idea for a street car, too risky having fuel right there at the corner nose/fender area with no real protection... have you seen what these cars do in even a mild mph accidents? no thanks.

i run a robbmc 1100 pump & his 1/2" pickup with 1/2" & -8 line from tank to pump & pump to carb, only have issues about half the time on good runs, sucks when you get good 60ft & 1/8 mile time/mph only to have the car nose over at top of 2nd gear! the next step will be an electric in tank pump, but the robbmc runs so good as is & has allowed for some pretty good times considering the combo, stock 72cc O port E heads, HO intake & Q-jet, 3.23 gears, continental 3200 th400.

also the "high quality" anchor mounts are made in korea. something to consider to strengthen the driver side mount is to make you own mity mount by running a .25 cent 3/8" bolt through it which is all mity mounts are, they use the same anchor mounts & grind the "made in korea" off to try & fool people. i have made a few of them & the original one is still doing good in my car after 6+ years of drag strip & street abuse. but i also run a simple chain from the front driver head down to the frame as a limiter & im sure that has helped the mount live longer.

[besserspat]

78W72 thats great news on the engine mounts, I was maybe considering fabbing solid mounts in order to squeeze some space for the air filter but I have always ran 2" drop based air cleaners on second gens due to their lack of hood clerance. I am running a stock 73 flat hood.

We have a very similar set up except your heads are aluminum and flow much more. I've built a 10 bolt with 30 splines , Moser Axles, a True Trac and 3.08 gear. I like the 3.08 for obvious reasons on the street but also because Ive always liked the results with numerically lower gears and nitrous in the quarter.

Building a car that does double duty is always a load of compromise and from experience I tend to always favor the street more than strip performance when it comes street legal vehicles.

As for the small fuel cell / surge tank in the nose I hear your concerns , I had them too, but when I look at the original 13 gallon fuel tank in the nose of my of old 911 Porsche with very little protection around it... and the fact that I ride motorcycles too ... I guess im a punk that feels lucky !

[78w72]

i have a formula hood on my 72 firebird, same crappy hood clearance as the flat hoods, i run a factory dropped 1978 W72 air cleaner that just barely clears but allows for a 3" tall air cleaner.

i have a 10 bolt with an eaton 30 spline & moser axles too, i picked the 3.23 since its mostly a street car, far from ideal set up for drag use with a auto-x/handling intended suspension & no traction aids... have to roll into the throttle off idle or the drag radials will spin even on good track. but for a multi puprose car im happy with what ist done so far. a member on here "taman" has 3.08s & has got into the high 10's with them!

yeah i used to be a punk that felt luck too, had a 86 GSXR with a built up motor from a 93 & lower gears for drag racing that was crazy fast. but after some close calls on windy roads i sold it & stick with cars with gas tanks in the rear!

[besserspat]

Originally Posted by 78w72

yeah i used to be a punk that felt luck too, had a 86 GSXR with a built up motor from a 93 & lower gears for drag racing that was crazy fast. but after some close calls on windy roads i sold it & stick with cars with gas tanks in the rear!

Good ol flatsided oild cooled GSX-Rs, I still have a couple of those in the attic among my old bikes.

One is a 1985 GSXR 750 with a 1100 (1127 suzuki) but 1340cc , big bore block , 13.5 CR, big valves , Big ports with epoxy rocker head , big cams and Lectron carbs, fun times but really not user firendly lotsa fond memories on that bike and earned its keep.

The other is a '88 750 with a now 1216cc from a 1990 1127cc, ported and polished small port, shim head, FCR 39 carbs. stock suspension and chassis.

Im a motorcycle fanatic at heart , raced em, still built em, but cars proved to be so much more practical and inclusive when it comes to move the family, the dog and tools around...

[78w72]

Originally Posted by besserspat

Good ol flatsided oild cooled GSX-Rs, I still have a couple of those in the attic among my old bikes.

One is a 1985 GSXR 750 with a 1100 (1127 suzuki) but 1340cc , big bore block , 13.5 CR, big valves , Big ports with epoxy rocker head , big cams and Lectron carbs, fun times but really not user firendly lotsa fond memories on that bike and earned its keep.

The other is a '88 750 with a now 1216cc from a 1990 1127cc, ported and polished small port, shim head, FCR 39 carbs. stock suspension and chassis.

Im a motorcycle fanatic at heart , raced em, still built em, but cars proved to be so much more practical and inclusive when it comes to move the family, the dog and tools around...

1st gen GSXRs are my favorite, they lack the modern technology but are by far the best looking IMO with the notchback rear & dual headlights. mine was just a 750 that the prev owner who was into drag racing bikes built, wasnt too crazy, just a small bore & ported heads with modified mikuni carbs & individual K&N filters. the rear sprocket was huge, probably equivalent to 4.11s on a car, i never took it to the track but prev owner said it ran mid to upper 10's with ease.

i had it in the late 90's to early 2000s & was one of the quickest straight line bikes in town according to the guy that built it, nothing i played with could touch it on short runs below 90-100mph. i borrowed a friends new at the time 2006 GSXR 750 with the new fuel injection, it was fast with high top speed but felt like a moped on shorter runs compared to my 86. wish i woulda kept that bike!

couldnt imagine a 1100/1340 built like that!