Scenario - Full body car (A,B,E Body) seats at OEM stock height and near OEM stock position...what aftermarket seats and mounts are you guys using & why....poly seats or aluminum and if aluminum...what angle? Looking on line, it appears that the aluminum seats are offered in 18° and 20° lay-back and have seen a couple at 10°...

Just my own experience: if the seat is too vertical it's a bit confining, especially if you have to wait in staging lanes.
OTOH, too much lay-back makes me nervous - I have a tendency to lean forward, and not use the seat back: the dreaded "air gap".

I used Kirky Pro Strteet aluminum seats in my Dart.

https://www.summitracing.com/parts/kir-41900

While many of us did most of our drag racing with a poly seat IMO No racer should use such an unsafe piece of equipment--a seat IS a piece of safety equipment---In a crash the inserts pull out of the seat bottom and you are toast--Kirkey makes aluminum seats cheap enough now days--and when mounted correctly ( a very big deal) you are much safer than in a poly seat. Poor seat mounting is very common and puts you at great risk in the event of a crash.

Im a big fan of the BAJA style seat from Corbeau. there is a big selection and all good for racing applications.

http://corbeau.com/catalog/product/view/id/133/category/78/

I've always used the poly seats with the cover. The seat itself is too light to worry about pulling out the inserts. The harness is what keeps you in place. As long as you have good mounts on the straps, you aren't going anywhere. I use the 2 piece mounts and angle the seat to where is comfortable for me. I can almost fall asleep in my seat.

This is just me ....but I never was a big fan of the aluminum seats they look uncomfortably for me, the poly does it for me.

... the proper way so set up a seat is to angle
the front up to support your legs... with your foot on the
pedal... the back of the seat can be back a little from 90*
from the seat itself... but the front is the important part..
if the back of the seat is against the cross bar its not going
anywhere... the belts hold you from going forward and up

X100

Those who say other wise have never crashed and it should not even be a question now a days like said above. GO Aluminum!

This reminds me of this...

I've never been in a wreck at the track, but I have to side with crabman173 and Challenger 1. I'm also concerned about the inserts pulling out of a poly seat. I'm not saying that poly seats are "unsafe", because they do help "confine" you within them and the belts help by being routed through them. I had poly seats in my bracket car. They have many benefits over OEM buckets and bench seats. But I believe aluminum is much safer and stronger. As for comfort, you can always add padding.

You have to remember, the seat belts DO NOT stop you from moving forward, up, laterally, etc. They LIMIT your movement! Seat belts WILL stretch, the seat can move around due to your weight and poly is weaker than aluminum. To me, it seems that insert "wallowing & pull-out" in poly appears easier than "wallowing & pull-through" in aluminum.

Of course, there are no guarantees. Each wreck is unique and weird things can happen. The severity of the accident, proper mounting and many other variables come into play. But I decided on aluminum Kirkey seats for one of my two 11-12 second cars to replace the OEM seats. I just haven't had the time or decided which one to put them in.

Anyway, that's my perspective.

I have had the inserts pull from a poly seat on a launch years ago BUT....that was because the seat was not as secure as it should have been and at that time.....the crotch strap was not properly installed....

If you lived closer and wanted a alum seat I have one
thats never been in a car... I didnt like it and bought
a poly one.. if anyone wants one cheap..$70.. come get it
its up in the rafters in my pole barn.. along with some
other stuff that never made it on a car.. like a hood scoop

The seat mounts DO NOT hold the seat in the car. For Christ sakes, Pro-Mods and similar have the damn seats held in with dzus fasteners. You think those keep the seat in the car in the event of a crash? The BELTS hold you AND the seat in the car. If your belts let you and the seat move around a lot in the event of a crash......either the belts are not mounted correctly OR you did not have them tight enough

The poly seat only weighs a few lbs. which is a very small percentage of most of our body weights.
It's not going to matter what kind of inserts it has.

If you look at how complicated the seat mounting is in a NASCAR ( they are installed RIGHT!) and then you look at the lame A$$ way most drag racers mount the set and belts you will then see my point--Drag racers usually do a crappy job --follow no instructions --or even care--Until--they have a crash and learn the hard way just how much you can move around in a car with belts tight as all get out--YOU MOVE a LOT!
Minimizing the chance for injury is all about a well designed seat that fits YOU not the average guy--all circle track seats are custom in NASCAR for a reason--you go get fitted then seat is built for you--then..more attention goes into mounting than than almost anything else.
Read, study, ask the makers of safety equipment and make your car MUCH safer! Or not...
Every violent bracket car crash I have ever seen the seat and belts did not do the job and were detached, deformed, etc which for sure added to injury--
I run a front engine dragster with a very snug drivers compartment to say the least--I am belted in so tight I can hardly breathe--I had a rough shut down on a crappy/ bumpy track recently and was VERY surprised how much I moved in the cockpit--a ride like that in a door car and poly seat and I would have been in the back seat
FWIW many Pro mod type cars fly all to pieces during a crash--everything leaving its original mounting spot--they may follow NHRA specs but those do not promise or mean it will not bust into a 1000 pieces and save you --it is not much more than a little common sense --it is not all "scienced" out so yea--they have Dzus fasteners and most everything else on them is too light and prone to break off with the least little bump
One out of 20 bracket racers can tell you what seat belt mounting angles and shoulder belt height etc should be the others are just lucky they have not crashed.

That is very dangerous advice in the op's context.

The OP car is not a pro mode and I am betting it don't have a funny car cage in it either.

I disagree... the weakest point in a seat mount is the stanchions
itself... not the seat holes... the stanchions would be the first
to go... 99% of use make them out of alum for weight.. the seat
belts do their job of containing the driver... they always have..
it you have a taller seat frame its the first thing to break.. but most of use keep the seat close to the floor with only the
front raised up for angle... I've seen multiple cars roll and the
plastic seat was still in tact when it was over... because the
belts held it there(with the driver)

I would say set in one before you buy. The poly seats are one size fits all. I'm here to tell ya my butt don't fit that well in a poly seat, very uncomfortable .It might be OK for a few minutes at the track but I drove my daughters Jeep about 1/2 mile and couldn't wait to get out of it. Kirkey aluminum fits and is comfortable in the proper width, 20 lay back for me. Just my opinion, others my differ.

Love my aluminum Kirky, I can sit comfortably in it during numerous Chevy an Ford oil downs, no problem.