im trying to find a pressure plate for my 400 small block, but i dont know what size my current T-5 transmission pressure plate is. I dont want to waste the money on buying the wrong one. The flywheel i found was set up for an 11inch clutch plate, but i have a hard time believing the T-5 is 11 inches.

 

The T5 bellhousing can only accommodate a 153-tooth flywheel.

http://www.summitracing.com/parts/MCL-460300-2C/

 

i thought that too...until i went to the local parts store and found out i would need a 10.5in plate to match up a flywheel and that is available in the 168 tooth model.

http://frugalmechanic.com/auto-part/...490%2010%20132

 

Your missing the point five7kid made;
It doesn't matter what size flywheel / clutch you " can " actually bolt to your 400

You can only physically fit a 12 3/4" (153 tooth ) flywheel in the T5 bellhousing so you need a clutch
that fits a 153 tooth flywheel

Seeing that you are restricted to a same as stock size flywheel ( but to suit a 400 ext balance)
why would you not just use a stock T5 clutch plate and cover ????

 

For the decades that I had a 400 in my car, that's all I did... worked great. Stock size disc too. I didn't use a "stock" clutch of course, just, "stock SIZE".

 

ok, so i would need the 153 tooth flywheel so it fits the bell housing thats 12.75". and whats is the T-5 the 10.5" or 10.4"?....And on another note what would i need for a starter to reach the smaller flywheel?

 

Im just recently getting my swap on the road, but here is what i did for my 400/T5 combo.
I bought this little weight plate that goes in between the engine and the flywheel so that it has the external balance. Summit sells this. I then bought a normal 153 tooth flywheel for a regular ole 305/350 motor. Then I bought my clutch. It was a stock sized clutch but a stronger then stock one.
For a starter your going to need to check to see if you have the inline starter bolt holes drilled already on the block. If you only have the staggered holes then you need to have one drilled and tapped. Learn from me that you want to do that part before the engine/tranny is in the car. It is a royal pain to drill and tap that hole with the engine and tranny in the car all bolted up.

 

Yes the flywheel is 12.8".

Yes you would use the clutch disc that is 10.4" in dia but often called 10.5".

The other guy is exactly right about the starter bolt hole... I've posted that so many times, complete with pics and measurements and a sufficiently detailed explanation that your average 5-yr-old can figure it out; .... I'm always amazed when people STILL try to put that combination together without it. You ABSOLUTELY MUST MUST MUST WITHOUT AN ALTERNATIVE have the right hole, or your WILL NOT be able to put a starter on the car that will work.

Once you have the hole, you need either the stock 305 T-5 starter (just because it's "possible" doesn't mean that it's necessarily "a good idea"... note also that an auto starter will not work, although most starters nowadays have a T-5 nosepiece anyway, but you just never know) or a LT1 T-56 starter or a mini-starter with the appropriate bolt pattern (usually advertised as "dual pattern" or similar). I HIGHLY recommend the aftermarket mini route.

 

So my current 305 flywheel will work with the weight plate that i just looked up...i have a new stock sized clutch to account for the 400ci. And my 305 starter will also work with an inline bolt pattern.....Which im not sur if i have, there are just 4 threaded holes for the starter at every corner of the bottom of the 400 where it bolts up, a pic of the inline pattern would be helpful, i just cant seem to find one.

 

Maybe
You haven't told us yet what year your 305 motor is
Not all years the same bolt pattern as a 400ci

 

Where you lookin?
There will be 2 or 3 holes ONLY on the starter pad on the pass side of block;

 

i have those same three holes plus one more alittle right of thecenter about half way up that looks clearly drilled by the previous owner. My 305 motor is a 1983, and the 400 is a 1976. I also looked up the external balancing weight plate bolt on a didnt find one for an external balanced 400, my search turned up a buch of stuff for a 383 and 454.

 

You should be fine then using your flywheel off your old 305. Since they are both 2pc rear main seals. Here is the exact plate that i ordered from summit when i ordered my clutch/flywheel setup. http://www.summitracing.com/parts/QTI-RM-525/

Edit: The easiest way i can think of to check to see if you have the correct holes would be to mount your old starter off your 305. It should be the inline pattern.
P.S. Be carefull with that 400. I JUST licensed/registered and insured my car a week ago today and put 70miles on it weds and it ran PERFECT then yesterday it started smoking like heck out the pass. side header which led to that side head coming off and me finding #6 piston had a section come apart at the crown. So its now out of the car....again..... Im thinking head gasket caused it. But dont know for sure and prolly never will.

 

Thanks for all the help, the 305 removal is almost complet and i can finally see if the flywheel and plate will work out.

 

I ran into another slight problem, where the arm for the clutch bolts up to the old 305; the 400 does not have that bolt hole, what should i do regarding to mounting the clutch arm/linkage to the block there?

 

Is this a mechanical clutch linkage? On my T5 hydraulic setup there isnt anything bolting the hydraulic stuff to the engine.

 

Yup; get rid of that Stone Age linkage crap if your car has that, and put a hydraulic setup in it.

By the time I first put a 400 in my car back in the 80s, I had already LONG SINCE done that. I think I updated mine to hydraulics in around 1985 or 86. HEEEEEEEUUUUUGGGGGE improvement.

 

About how much would a hydraulic set up run?

 

Check your nearest junkyard

Think I paid like $75 for the BH, flywheel (which I didn't need), clutch (ditto), pedals, hydraulics, and some misc. Who knows what it would cost you, today, somewhere else (maybe)?, and so forth.

Definitely cheeeeeeeeeeper and better END RESULTS than whatever hack job and alternate-ethnic-engineering you could do to hack that old Stone Age garbage back in there. Consider it a sign from Above that it's time to modernize.