5.3/LS3 Small Bore | Factory Mast | As Cast | Cylinder Head - Pair

5.3/LS3 Small Bore | Factory Mast | As Cast | Cylinder Head - Pair

Marsoni

M251S

$1024.50

Get it in 3 business days with 1 day shipping. Friday, May 29

5.3/LS3 Small Bore | Factory Mast | As Cast | Cylinder Head - PairIntroducing one of the first 5. 3 Liter LS3 cylinder heads designed for use with the LS3 intake without adapters. Optimized for 3. 780 bore diameter. ***Download the Tech Sheet Here*** We launched our Factory Mast product line to deliver an economical product line for our customers. You have come to love the "Black Label" Cylinder heads, but now you can get the same quality at a lower price without SACRIFICING performance. Manufactured using permanent

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Exchange/Return Notes

We offer a 30-day return/exchange service after receiving.
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Got this to replace cabin air filter on 2020 Honda Civic Sport, as it said it was a direct fit… It does fit but not perfectly! Holding it next to the filter you can see the size difference, with the original being slightly longer. I noticed a whistling sound from the AC at full blast right after install. I believe this noise is caused by the small gap left in the retainer box with the slightly smaller filter. Luckily it is not incredibly loud, but it’s still there. The quality of filtration seems to be much better than stock filter, but the fitment not exact for vehicles mentioned above.

WAS THIS REVIEW HELPFUL?YesReportShare

Reviewed in the United States on May 17, 2026

Verified Purchase

Bon43

Chelsea, US

★★★★★ 5

Awesome

Easy to install. Fit appropriately. Value for the money for sure.

WAS THIS REVIEW HELPFUL?YesReportShare

Reviewed in the United States on September 26, 2025