How to Install a Big Block Engine - 1967 Chevelle

I’d like to say that I wasted no time once I had the car mobile enough to change position in the garage. I won’t say that though, because it would be a lie. After a busy springtime and gathering many more parts, I was finally ready to move on to the next stage of assembly: the drivetrain.

I bought this Big Block on Earth Day of 2014 which seems like a fitting tribute for an engine that may even attain double-digit MPG. It was on our “Garage Sale” because it had been part of a display chassis used to highlight new products available at Speedway. It since had been discontinued in this configuration because of the scarcity of original iron heads to be used as cores.

This engine was offered as a Speedway exclusive and has a flat tappet cam and came with intake and HEI installed. Just like all the other complete BluePrint engines that we offer, it was run on the dyno and was shipped with the results. Since the time that this engine was built, they’ve changed cam profiles a bit and offer similar packages but this particular engine interested me because while making relatively low horsepower numbers for a big block, just 503.8HP @ 5,500 RPM, the steel stroker crank helped crank out impressive torque numbers of 578.3 lbFt @ 3,800 RPM. All that power on 9.5:1 compression and pump gas. Sign me up.

After over four years in the corner of the shop, this dog was finally going to have its day. In preparation, I had a stout TH700R4 built to handle the task of changing gears through that flat and strong torque curve. Coupled with the tame 3.50:1 gears in the rear end, this combo should do a pretty decent job of using the ultra-low first gear in the transmission while allowing lock up in fourth gear to try and salvage some fuel economy. I chose a 3400-3600 stall TCI Street Fighter Converter with lock-up to make the most of both ends of the spectrum.

Here’s where the Chevelle guys are going to start worrying. I mated the engine and trans together on the garage floor and installed the starter to avoid the task later. Once I had the new poly motor mounts bolted tightly, I picked up the whole works on the trusty cherry-picker and adjustable cradle.

I’ve installed literally dozens of engine/trans packages this way, clear back to my Disco Nova in high school. Two small blocks and eventually a solid cam 396. What I learned this day was that the Chevelle’s relationship between the cross member and trans tunnel is somewhat unique.

No matter what angle of attack I tried, there seemed to be no physical way to get the oil pan to clear the cross member without the transmission hitting the top of the tunnel first. Immediately I blamed the aftermarket Milodon pan. Surely a factory Chevelle pan would not offer this amount of resistance. After some quick internet research, I deemed that it looked as if the slightly deeper, but not much shallower sump on an OEM pan would actually make the problem worse. So now what? At this point, we were six hours into what I had assumed would be a two-hour job.

My adult supervision was ready to go home for the day and I needed a second set of hands for whatever step came next. I decided to pull the whole works back out of the hole and regroup the next day. My buddy Jay went home.

Then I went back out to the garage.

I’d come too far to give up. Even if it meant only achieving part of the day’s goal. I separated the engine and trans and in fifteen minutes I had the engine set in place.

I discovered that the engine mounts and ARP bolts did a fair job of supporting the engine without the rear motor mount to assist. That being said, after I was able to get the car back on the ground I supported the oil pan with a jack and 2”x12” to spread the load on the oil pan sump. The transmission would just have to wait until the following day.

It was at about this time that the Chevelle guys are going to scream “YOU FORGOT THE HEADERS!”. I know because just that thing happened after I posted a Facebook update showing the days progress. I reassured them that I had a plan on tackling that task very soon.

I guess you’ll have to continue reading to find out who was right.