Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   Do It Yourself, Boating on a Budget (https://www.offshoreonly.com/forums/do-yourself-boating-budget-249/)
-   -   489 Stroker (https://www.offshoreonly.com/forums/do-yourself-boating-budget/387740-489-stroker.html)

THUNDERBOLT19 04-03-2026 01:41 PM

489 Stroker
 
I have a 489 BBC to replace my blown 516. I would like to reuse the cam from 516 if possible.
275/284 112lsa (Isky 39627584)
Holley 850
Dart Single plane intake

trying to decide what heads to get on a budget. Can get a good deal on a set of gm 088 heads locally but not sure if they’ll be sufficient enough.

any input would be great

Looking to get around 550+ hp

Tartilla 04-03-2026 03:50 PM


Originally Posted by THUNDERBOLT19 (Post 4945443)
I have a 489 BBC to replace my blown 516. I would like to reuse the cam from 516 if possible.
275/284 112lsa (Isky 39627584)
Holley 850
Dart Single plane intake

trying to decide what heads to get on a budget. Can get a good deal on a set of gm 088 heads. Looking to get around 550+ hp

You're looking for a single set of 088 heads?

What do yoy mean by budget? Getting a used set of heads cleanup up could be more than new afrermarket aluminum.

THUNDERBOLT19 04-03-2026 03:52 PM

I can get a good deal on gm 088 heads locally but not sure if they’ll be sufficient enough to reach my hp goals. The heads I can get locally have new valves and valve job done by machine shop. Ready to go on engine

Tartilla 04-03-2026 03:57 PM


Originally Posted by THUNDERBOLT19 (Post 4945458)
I can get a good deal on gm 088 heads locally but not sure if they’ll be sufficient enough to reach 550-600

088 heads were on the 800SC Merc Racing engine. They'll flow sufficiently for 600hp. The issue is they have about the worst exhaust port GM ever made. They also have the non-adjustable rocker stud system. $$$ to drill/tap for 7/16 studs....or use the ARP 3/8 to 7/16 studs.... but not the best option for the cam you'll need for 600hp.

What WOT rpm are you lookong at for 600hp?

Tartilla 04-03-2026 03:59 PM

088 rec port heads are very lazy...and have poor valve seat throats...so no real valve job shape. The only way to correct that is to put larger valves in. More work...more cost.

Sporl Performance 04-04-2026 12:15 PM

I have 2 pair Merlin oval port heads.1000.00 Pair
Ron 504-616-6005

Osiris58 04-04-2026 02:53 PM

If you are targeting 550+ hp, the 088 heads will work but will likely limit power without porting. They are okay for a budget build, but better flowing heads will make it much easier to hit your goal.

Tartilla 04-05-2026 10:49 PM


Originally Posted by Osiris58 (Post 4945492)
If you are targeting 550+ hp, the 088 heads will work but will likely limit power without porting. They are okay for a budget build, but better flowing heads will make it much easier to hit your goal.

GM marine crate 454s with carbs and 088 heads...FT hyd cam 224/224 0.510" were 390HP at 5200rpm.

Not 100% on what the intakes were...probably iron. A good dual plane would help out there.

088 heads typically have factory cut valve seat throats that are just hogged out round and flat. Makes doing a quality valve job almost impossible. Increasing valve dia is an option...but 2.19" is very large already. The bottom of the Int ports is very low velocity.

Peanut Ports with a little bit of simple work would be better options...and can be had for $150/set used.

BillK 04-07-2026 07:27 AM

What compression ratio is it going to end up at ?
Personally I dont think that cam is going to be enough to reach your goal but I would call Isky and tell them exactly what you are trying to accomplish and see what they say.


All times are GMT -5. The time now is 10:39 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.