These style, (not necessarily endorsing this brand rings), is what I use and recommend for TBI, however the investment on a carb'ed fuel system is very much worth it:
https://www.amazon.com/dp/B0CCYLCCXL/
$19.99
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These are SAE sizes for PEX, which has a standardized wall thickness. These are imported with a range of SAE sizes.
The trick is to clamp as much as possible without bottoming out the crimp or crushing and therefore cutting the outer layer of low/high pressure fuel lines.
This is the crimper that works for me:
https://www.amazon.com/dp/B00LWR4T6Q/
$21.98
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The crimper, (please buy the one with the gauge), is adjustable with a go gauge for resetting to the exact crimp specs for the size pipe or hose you work with. I use it for a lot of other things besides my fuel lines. Water hose repairs with the larger size rings, vacuum seals with the tiny ones and silicone hose, Electrical wire shielding, when adding a layer of rubber insulation or metal shielding to a wire protection protocol, especially where e-tape would not hold up to abrasion. This is the tool to install OEM boots on your CV joints, instead of the home owner weak sauce clamps they send you in the DIY boot repair kits, (which are junk fold back clamps that leak water into your CV Joints).
Shop Compressor air lines, at the ranch?
How many leaking stoopid 1/2" hose clamps on 3/8" air hose, have I replaced?
All of them.
Who cares if the ranch compressor burns up or gets full of water all winter?
It ain't my problem, (or my money to replace it), right?
This set of crimps, offers metric sizes, which may offer better crimp/seal ratio on rubber hose with nominal ID and variable OD.
https://www.amazon.com/dp/B07XJB5D6L/
$23.00
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You don't want to bottom out a high pressure fuel line crimp before it reaches a solid seal.
You alternatively, do not want to under-crimp, by using too small of an un-crimped ring, which does not crush less than half the crush capacity of the range of the clamp. It's important to discuss range of clamping size: 13.3mm - 11.3mm, anywhere beyond 12.8mm would probably be OK, because the ring has to fit over the rubber hose. The clamp has to function within a range of use. Close to maxed out is better, without cutting or deforming the outer layer of rubber fuel line. It's not exact, but it is very reliable when performed without a beverage in hand and careful crimps.
What happens on the INSIDE of a repaired metal line, also MATTERS... so keep reading!
2-3 of these, offsetting the crimp, if possible, is very reliable on 35-85 psi Fuel lines. Try to add a lump in the line or slight flair to the end with a filed edge, so the tubing does not cut the inner layer during the crimping process. Diamond files to the inner fuel line and outer flared edges are what is required to succeed. It's detailed work. You'll need your magnifying lenses, if your eyes are getting like mine, to perform it correctly.
Just remember, if the crimp looks like the space between the clamp is no where near maxed out, it requires using an alternative SAE or MM ring size, so a majority of the crimp space allowed, is used, for best clamping ratio.
Posted a lot of TBI and EFI fuel line info before.
Look up WarHawk in the search or click on my sig for the threads regarding modding your carb to TBI or EFI or safety recommendations for any fuel system upgrade.
You do NOT have to buy all of these assortment packs to fix your engine fuel system.
Buy the sizes in smaller packs that match the diameter of the exact lines you want to fix.
The tool is the upfront cost and very worth it. My power steering lines never leak, since using this tool on my engine.
I bought the swivel style brass push on fittings with the yellow plastic ring, for the P/S Saginaw box, so I can wrench them off without twisting the lines, due to the crimps. It works great. No B/S, no leaks. The o-ring style modern 14mm P/S fittings have the tubing and these work great for that as well.
They even added the lump in the tubing for you!
Just cut the crimps off, replace the P/S lines with new-er rubber less than 5 years old and use these to replace the factory crimps.
It will work for A/C systems, in a pinch, as well. As the pressure rises, the number of extra crimps rises too.
Do NOT use these on Brake LINES, ever.
Do NOT use compression fittings on Brake Lines, EVER.
Do NOT use these for PLASTIC FUEL LINES EVER. Without the flare, they will slip under pressure, no matter how many you use!
If you have metal fuel lines that broke, you can flare slightly,
file to remove the burs and crimp a quality rubber line *** "to flex or re-rout the hard lines"****,
using donor tubing from any engine scrap pile,
so long as it is very close to diameter and not extremely oval-ed out from being too close to a bend.
The quality of the rings can and will vary, so measure twice and read the reviews on thickness and clamping quality.
Pex is the best $. SharkBite makes these too $. The metric version tends to be a bit thinner, so double up, when you can.
The video's in the WarHawk thread, which show a square body burning up in traffic from an improper fuel system plumbing leak; are worth the research.
Everything matters, all the time, especially in the rubber hose and fuel system of your SquareBody.
Give yourself a few extra inches of hose, so if you have to cut and repair, there's enough line for a few rebuilds or mods.
Bad crimps happen, plan for them. Re-order the one's you'll need to fix R&R the system, as you go?
*** Fuel line rubber gets out of date every five years.***
Re-read that, please?
Steel hard lines last much longer. Copper is NOT used for gasoline engines.
Change your carb or EFI or TBI rubber fuel line with date coded fuel line often, (every 5 years), for excellent results.
The barricade layer in EFI Gates Barricade is on you! Not Gates.
Neglecting the date codes on tires and fuel line will cost you more than you think.
My acquaintance in the rubber hydraulics lines for aviation once told me: "Once you get into the aviation rubber business, you never get out!"
If you cannot correctly go-gauge the tool mentioned in this thread or you have no experience crushing fuel lines with a crimper or measuring the diameter of new non-rotted fuel lines, seek professional help and dump your wallet out to perform these repairs to a reputable professional mechanic.
If it looks wrong or the hose is rotten, throw it out and do it again!
It's a hobby. You will fail and learn. Try not to burn up your truck during the learning curve?
My $0.02, YMMV
If you put those low quality Chicom fuel clamps in my old, low pressure fuel system, in my aircraft; I would hunt you!
