88 TBI factory fuel lines - what portion can withstand high pressure?

[tlenzi]

Hello,

I'm in the middle of an LS swap and need to address the fuel lines. I understand that the front portion of the fuel lines cannot withstand high pressure and plan to change those out to PTFE braided hose, however the rear portion that connect to the fuel tank seem more substantial - can they withstand high fuel pressure? Has anyone retained these in an LS swap? It all fits so nicely and I'd rather not change them out unless absolutely necessary as I plan to keep the hard line portion regardless.

Thanks!

 

[97 bowtie]

What year is your truck ?

 

[97 bowtie]

My bad it says it in the title

 

[SAATR]

What year is your truck ?

Probably an 88, as seen in the title.

OP, at 32 years old, I wouldn't trust any rubber hose, much less at increased pressure. When in doubt, swap it out.

 

[arrg]

Probably an 88, as seen in the title.

OP, at 32 years old, I wouldn't trust any rubber hose, much less at increased pressure. When in doubt, swap it out.

Definitely this. Here's a pic of the crusty rubber on the supply line on my 88.

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I replaced it with a short section of PTFE.

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As for the front section, it should already be PTFE.

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I replaced mine, but when I cut it open to check its condition, the inside looked fine after 32 years and 292K miles.

 

[tlenzi]

Thanks for the replies. This is an 88k mile truck that's been garaged it's entire life. The hoses look great from the outside, though I know that doesn't tell the whole story. I was under the impression the fronts were not rated for high pressure. They are steel braided which I'm told was only done for the first few years. If they are PTFE I may choose to use them.

Any other thoughts out there? I'm not fishing for a particular answer, just curious what others have done or experienced.

 

[Erik the Awful]

I put a Vortec fuel pump in my '89's sending unit and the factory braided hoses hold the pressure just fine.

That said, I still gotta fix the oil pan leak and get it on the road. Nothing validates the reliability of a modification like actually getting miles on the road.

 

[Dropped88]

My 88 has been ls swapped over 2 yrs and the rear hoses are holding up fine also swapped a 95 astro. Has rear hose similar to gmt400 and its also holding up

 

[tlenzi]

Thanks everyone for the input. I'm going to reuse the rear flex lines and run new PTFE lines on the front flexible portion. The fronts are being changed out more for fitment reasons as they no longer stretch far enough to reach the new fuel rails. If I have any issues with the rear portion of the lines I'll update this thread for future searches by others.

 

[454cid]

Thanks everyone for the input. I'm going to reuse the rear flex lines and run new PTFE lines on the front flexible portion. The fronts are being changed out more for fitment reasons as they no longer stretch far enough to reach the new fuel rails. If I have any issues with the rear portion of the lines I'll update this thread for future searches by others.

Where are you finding ptfe?