Look what happens when you turn 67

I had the engine off and made an independent suspension system, lowered the seat, changed steering angle with a u joint. New running boards and fenders.
Everything was going great.
Put the engine back.
Totally FORGOT about the exhaust. Now it doesn't fit.
What are my options? I don't have a tube bender for 1 inch pipe and my welding
of thin metal sucks. I do have a lathe and milling machine though.
I was thinking of flex tubing.

That's some very clean and professional fab work on the suspension! Well done sir! I think flex tubing will be fine.

I've used plumbing fitting to re-arrange the exhaust on Briggs twins.
Using pipe nipples, 90's, 45's, and street ell's. (I have access to lots used of 1 inch plumbing fittings, pipe and a pipe threader.

If you will remove one of the exhaust pipes at the engine and check I think you will find that the block is threaded inside the exhaust port for 1 inch pipe.
After I got the exhaust pipes in the desired direction I just used a 1 inch threaded small engine straight through muffler on the end of the pipe.
I rigged some with dual exhaust headed towards the rear. Exhaust sounds like a glass pack muffler on the Briggs twins.

Also Briggs used lots of different type exhaust slip fitting for the different type of exhaust layouts.

Neat work on the Independent suspension.

Is that ATV/Motorcycle shocks?

The exhaust on my engine is 3/4 npt. I did buy a couple of fittings to experiment with.
I was looking at an atlas muffler AT-0123 that has 3/4 inch threads. It is for 8hp.
I thought 2 might work as dual exhaust .The engine is 19 hp.
The shocks are cheap bicycle shocks from Walmart.ca. There is no shock system as I found out, they are just springs to look like real shocks. You get what you pay for. They do work well as springs.