I put new heads , cam and intake on my 280 TRS's. Where do I start?

hard to tell, my 377cid made 380hp at dyno. 39 main rods. 73 main jets. CE secondary rods. P hanger.

Thank you, ill pop the tops off and see whats in it. It wont run below 1700 rpms now.

You may want to consider a wideband 02 sensor so you have some idea which way to go.

What size engines, static and dynamic compression, cam card? It should still idle, check your timing and check for air leaks between the intake and carb or intake and heads.

Its a 350cid (1975 L82 short block) changed from 76cc heads to 64 cc (so about 10:1 ) with 190 cc intake runners, Compcams extreme marine Advertised Duration 278/292, Lift .498/.500, dual plane air gap intake with stock 280trs carbs (7044290) I have sprayed BOTH engines intakes with carb cleaner !!!! Both act the same. No change in rpm. If I block the air horn it will speed up a lil.

Sure it's not sucking in water and stalling it ?

Does the samething when dry fired.

What part number is the intake? If it's a square bore intake there may not be enough flange to seal the carb on a spread bore carb. Edelbrock makes an adapter plate that's only an 1/8' thick for just this. Might be sucking air around carb base.

This one ?
https://www.summitracing.com/parts/c...44-4/overview/
Brand:COMP Cams
Manufacturer's Part Number:12-244-4
Product Line:COMP Cams Xtreme Marine Camshafts
Summit Racing Part Number:CCA-12-244-4
Cam Style:Hydraulic flat tappet
Basic Operating RPM Range:2,000-6,200
Duration at 050 inch Lift:234 int./244 exh.
Advertised Duration:278 int./292 exh.
Valve Lift with Factory Rocker Arm Ratio: 0.498 int./0.500 exh.
Lobe Separation (degrees):112

If so, yeh,exhaust sucking water back is a huge possibility
#2, engine will probably ant initial timing somewhere between 16-20* BTDC
#3 the stock carb metering will be out too lunch. don't know what to suggest with your cam/comp....can't help you there as cams that large I have a Holley Carb on it.