took on large project 27 getting ready to start putting her back together with twins any adive would be appreciated

The magnums that had Volvo outdrives were frmed differently than the Magnums that had TRS drives. The TRS botas were on 32" centers (at least in 1974). The Volvo boats had a were on a narrower center-to-center measurement, I am guessing 26" to 28"... the bottom line is if it were a Volvo boat you have more labor ahead of you with your update. If you are sticking with Volvo drives, this is point is moot. The Volvo 280 was and is a good outdrive. We had big-block Chevy's with TRS, so an exhaust system to fit on 32" centers was hurdle, it can be done but to get tube headers, it would be a custom job from CMI on 32" centers, which is not the less expensive set. We used log exhaust manifolds with custom made S-tail pipes.

If you have TRS drives, raise the drives to the rib rail or higher, it helped in performance, but engine hatch clearance can be issue depending on what your engine height will be. All of this is driven by your budget and glass expertise. I think a set of Motown small blocks from Bill Mitchell (Hardcore Performance - World Porducts) and Bravo's would be a great set-up, the Bravo drive is a shorter leg than TRS, and with four and five blade props, you can get rather high X-dimension.

The floor had cut outs, to get us out of the wind, which helped. I preferred the drop-out bolster over the buckets, because with the floor cut-outs you could stand, and not be so high in the air while driving.

Your budget and time available are the key to your project, good luck.

Stephen

thanks the previous owners had raised the engine hatch and trs drives already tanks are under the floor in cockpit area had 3 man bolster ,changing to two single drop out bolsters and a back seat,tring to figue out where is best to put controls ...also wondering if this could be an old race boat?looking for history ,1975 vintage,purple 3man bolster 100+fuel tank behind bolster,trs drives?ring any bells thanks agian

Hello 27Magnum

What color is the hull and where did you find the Sport?

Mine was a 73 with a drop floor and tanks under the cockpit floor
was set up as a 3 man bolster when I sold it.

Thanks
Jim

hull color was white w/ purple 3man bolster, found in Miama area, hin# indicates it was originally orange/white 1975...tanks were in the forward cabin to start with. I moved them to the cockpit area after talking to Magnum for their advice. motors are 350's 30 over ,Big cams ,Air Research heads..ect. thanks Bryce

The tanks in our's were in the cabin, the floor had cut-outs. This helped in this application with weight distribution, because it was powered with big-blocks (originally smallblocks from the factory).

The tanks were already in the cabin

What is the best tool to use to cut the key hole in the Transom? Saws All? How do you keep the blade from wandering outside the line on the inside? Does anyone know the Transom angle of a 27 Mag Sport?

Did the measuring this weekend, how does 3 inches high sound? Top of Bravo drive ia about 2" below the rub rail curve.

that ones beyond my knowledge,my trs s are jammed up tight into the bottom of the rub rail, could not tell you about the bravos...sorry