SKU: 99208860340

Flowtech LS Swap Exhaust Manifolds - 31730-3FLT

Sale price$172.32 Regular price$191.47
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  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 17 - Jul 22

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Description

Flowtech LS Swap Exhaust Manifolds - 31730-3FLTOverview: These Flowtech cast iron exhaust manifolds have a 2. 25 inch outlet, natural cast finish and are designed to hug close to the engine block so they fit into a wide variety of replacement and engine swap applications at a budget friendly price. Being cast iron means they will provide years of leak free performance with less under hood noise than traditional headers. Plus, their shorty design means you can route exhaust tubing close to your

Overview:

These Flowtech cast iron exhaust manifolds have a 2.25 inch outlet, natural cast finish and are designed to hug close to the engine block so they fit into a wide variety of replacement and engine-swap applications at a budget friendly price. Being cast iron means they will provide years of leak-free performance with less under hood noise than traditional headers. Plus, their shorty design means you can route exhaust tubing close to your frame/floor pan for maximum ground clearance.

Features:

  • Intended for GM LS engine swap applications where durability and leak-free sealing is desired at a budget-oriented price
  • 304 stainless steel mating flanges included (mating flange fasteners are not included)
  • 2.25 inch outlet diameter offers improved flow for maximum performance from a cast iron exhaust manifold
  • 2 bolt exit flange configuration matches the E-rod exhaust manifolds for a factory like fitment. This allows the use of OE gaskets and fasteners if desired, for an OE quality seal and fitment to emissions devices
  • Cast from Hi-Silicon-Moly Ductile Iron to provide durability and corrosion resistance
  • Tight tuck design provides universal fit for most popular chassis and a clean traditional muscle car appearance
  • Available in plain as-cast finish or with black or silver ceramic coatings for reduced engine compartment temps and improved corrosion resistance

Application:

  • Universal

Specs:

Application Multi-fit
Brand Flowtech
Choose Your Part Manifold
Collector Diameter 2.25 inch
Emission Code 8
Engine GM LS
Finish Black Ceramic
Header Finish Black Ceramic
Header Style Manifold
Material Cast Iron
Primary Tube Dia. 1-3/4 inch
Product Type Manifold
Subframe Stock
Tube Material Cast Iron
Type of Component Manifold
Warning California Proposition 65
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 99208860340

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4.1 ★★★★★
Based on 17 reviews
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Verified Purchase
Allie
Waukegan, US
★★★★★ 4
Cute - SIZE UP
Size: 33, Color: Luxor Heat - Light Indigo
these are super cute and look very flattering but they run SMALL. I used to wear 32s in Levi’s but lost 30 pounds this year so I ordered a size down and they didn’t fit at ALL. I reordered a size 33 and they still fit tighter. My Levi jeans in a 32 barely stay on me anymore but these are snug in a 33. They’re still super cute and comfy, guess it gives me room to size down into them for awhile lol
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 8, 2026
C
Verified Purchase
Cherie
Bozeman, US
★★★★★ 5
I love these!
Size: 30, Color: Athens Mid Short - Medum Indigo
Wow! I got these for$20! They fit just like the 501 pants to me. . The only thing I'd change is s little less fraying on the front but other than that these are a broken in lived in look for $20!
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Reviewed in the United States on May 3, 2026
G
Verified Purchase
Grace
Phoenix, US
★★★★★ 3
Wish the sizing was more accurate, but still cute!
Size: 33, Color: Luxor Heat - Light Indigo
These shorts are super cute! I really love the color and style, but the sizing is WAY off. I typically wear anywhere from a 12-14 in jeans. After looking at reviews, I sized up to order what I thought would fit like a 16. Unfortunately they are pretty snug. I am hoping after a few wears they will loosen overtime. I would size up two sizes if you are a curvy girl like me! They do not have much stretch to them, but good quality denim.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 14, 2025
H
Verified Purchase
Honest reviewer
Los Angeles, US
★★★★★ 5
Perfect shorts!
Size: 30, Color: Athens Mid Short - Medum Indigo, Size: 30, Color: Athens Mid Short - Medum Indigo
I was worried these shorts wouldn’t cover enough of the butt area or that I wasn’t thin enough to wear them especially since most of the reviews are from thinner people. but OMG, they’re perfect. I’m 5 4, 152 Lbs and size 30 is absolutely perfect. Size 29 would be small for me.
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Reviewed in the United States on May 2, 2026
E
Verified Purchase
Eleven 11
Bozeman, US
★★★★★ 5
Cute distressed shorts but size up!
Size: 30, Color: Athens Mid Short - Medum Indigo, Size: 30, Color: Athens Mid Short - Medum Indigo
Love these shorts! These Levi’s run small. I usually wear a 28 and ordered a 30 because that’s what was available. I’m 5’1”, 135 lbs for reference. They’re distressed and shorter in front which are perfect for us short gals.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 1, 2026

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