L-29 heads question?
09-19-2023 | 08:45 AM
#11
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Joined: Mar 2019
Posts: 172
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L29 heads (I believe are 279 castings) are good for 450 max HP NA in my opinion with some light porting. The ski jump and the small valves really restrict flow over 4800.
But a cam, intake, exhaust, and some light porting on the heads got me a 10 mph gain on a 7.4 MPI in a 24x7. Also, I spin it to 5400 with no problem on the stock bottom end. The gen 6 block is a great starting point for any real-deal build later on as well.
But a cam, intake, exhaust, and some light porting on the heads got me a 10 mph gain on a 7.4 MPI in a 24x7. Also, I spin it to 5400 with no problem on the stock bottom end. The gen 6 block is a great starting point for any real-deal build later on as well.
03-23-2026 | 01:31 PM
#12
Registered
Joined: Aug 2019
Posts: 1,224
Likes: 415
From: BC
L29 heads (I believe are 279 castings) are good for 450 max HP NA in my opinion with some light porting. The ski jump and the small valves really restrict flow over 4800.
But a cam, intake, exhaust, and some light porting on the heads got me a 10 mph gain on a 7.4 MPI in a 24x7. Also, I spin it to 5400 with no problem on the stock bottom end. The gen 6 block is a great starting point for any real-deal build later on as well.
But a cam, intake, exhaust, and some light porting on the heads got me a 10 mph gain on a 7.4 MPI in a 24x7. Also, I spin it to 5400 with no problem on the stock bottom end. The gen 6 block is a great starting point for any real-deal build later on as well.
L-29 2.06 valves can flow a lot of air. 550-600hp easy.
With the steep chamber wall, going to a larger valve can hurt flow. The 1.72" exh valve is well sized to feed the efficient exh port. These heads have some of the best BBC in/ex flow ratios ever profuced.
Ported: with 2.06/1.72. 0.400" 242/189cfm 78%.
If anything, the swirl is too aggressive. With some mild porting help, they can really perform.
